Top 10 Ash's pokemon

10. Pikachu

Win rate 63%

Pikachu is Ash's first-ever pokemon and the most reliable one. In the first episode of the Pokémon anime, Pokémon - I Choose You!, Ash woke up late the day he was supposed to go to Professor Oak's Laboratory to obtain his first Pokémon. When he arrived at the lab, the three available starter Pokémon, Bulbasaur, Charmander, and Squirtle, had already been taken by other Trainers who had arrived on time. Seeing Ash's disappointment, Professor Oak gave him Pikachu, who, at first, did not care at all for his new Trainer, constantly zapping him and anyone else nearby. He refused to go into his Poké Ball, and when Ash failed to catch a Pidgey, he laughed at him. However, by the end of the episode, Ash gained Pikachu's trust by protecting him from an attack by a flock of angry Spearow. Seeing this act of selflessness, Pikachu defended Ash from the Spearow as well, and the two of them became inseparable friends, a moment that was capitalized on by catching a glimpse of an unknown Pokémon flying by. Ash then rushed to Viridian City to get Pikachu hospitalized quickly, as he had been badly injured during the fight. 

In Pokémon Emergency!, Ash managed to get to the Viridian City Pokémon Center just in time with the help of Officer Jenny, who scolded Ash for "mistreating" Pikachu. Nurse Joy agreed to heal Pikachu, and thanks to her, Pikachu managed to regain his health. At the end of the episode, Pikachu had regained enough strength to send Team Rocket blasting off for the first time.

Ash's bond with Pikachu is the strongest from the start of the series Pikachu has been there with ash.

9. Corphish

Win rate 63%

Corphish debuted in Gone Corphishin'. Ash and his friends were camping on a Dewford Island beach, and Corphish was attacking them from underneath the sand. Eventually, its identity was revealed and Ash battled it and caught it using his Treecko.

Corphish is a very brash Pokémon; it will often charge into things without thinking about its actions first, which usually leads it into some kind of trouble. Ash respected Corphish for its power, hence why he initially caught it. However, he struggled to teach Corphish how to handle its own strength, particularly regarding its pincers.

Corphish is prone to jealousy and had a rivalry with Ash's Treecko. In Go Go Ludicolo!, after Treecko evolved into Grovyle, Corphish was worried it would not get as much attention as the powerful new Pokémon. It is also an extremely gluttonous Pokémon; in A Shroomish Skirmish, Corphish ate all of Torchic's food. When it later got lost with Torchic, Corphish preferred to go on as if nothing had happened rather than swallowing its pride and apologizing.

8. Scraggy

Win rate 67%

Ash received Scraggy's Egg in Here Comes the Trubbish Squad! as a parting gift from Karena for helping her settle a conflict between her granddaughter Daniela and her students, who had befriended a Trubbish.

When the Egg started hatching in Scraggy-Hatched to Be Wild, Axew accidentally knocked it over in excitement, causing it to roll down a hill towards some sharp rocks, but Pikachu used Quick Attack to catch it in midair just in time.

Scraggy hatched from his Egg shortly after and he wasted no time showing off his headstrong nature. When Pikachu tried to greet him, he used Leer on him and then attempted to Headbutt him, but missed. Ash and Pikachu decided to have a small battle with Scraggy as a "welcome gift". Scraggy was easily subdued by a weakened version of Pikachu's Thunderbolt attack, while his attacks hardly did anything on Pikachu. He later tried to pick fights with Ash's other Pokémon, Pidove, Oshawott, Tepig, and Snivy. Since he was newly hatched, he was easily subdued by their weak attacks. Ash attempted to catch him with his Poké Ball but Scraggy refused, wanting to explore the outside world a little longer.

Later, Scraggy wandered off and started headbutting a tree that was the home of a group of Galvantula. He became paralyzed and was heavily injured by Galvantula's attacks and needed to be healed. With no Pokémon Centers around, Iris quickly made up a potion for him to cure his paralysis. He felt better the next morning and left to confront the Galvantula that attacked him. Again he was outmatched as the entire colony appeared to battle him and was saved by Ash and the rest of his Pokémon. Seeing what they were willing to do for him, Scraggy began to trust his new teammates.

After returning to camp, Cilan suggested that Scraggy battle Iris's Axew. The battle ended in a draw when both Pokémon knocked each other out. After the battle, Scraggy happily agreed to go inside his Poké Ball.

7. Gible

Win rate 67%

Ash first met Gible in A Meteoric Rise to Excellence!. Wilma explained that Gible was trying his best to learn the move Draco Meteor. But for some reason, the move always failed; instead of exploding in the sky, it always fell to the ground and hit Piplup. Ash wanted to help the wild Gible learn Draco Meteor and achieve his dreams. He successfully used the move against Team Rocket but failed again in his next attempt. By the end of the episode, Gible decided to start following Ash.

Gible is the first Dragon-type Pokémon that any main character has owned. He is also Ash's first officially caught Pokémon that can evolve into a pseudo-legendary Pokémon.

6. Snorlax

Win rate 73%

During his travels in the Orange Islands in Snack Attack, Ash arrived at the Seven Grapefruit Islands, where a Snorlax was eating everything in sight. Once it became apparent that it was a strong swimmer, concerns arose that it would consume the islands' vegetation within days. Ash, Misty, Tracey, and the Team Rocket trio attempted to take it down. However, Snorlax proved to be a highly defensive and very powerful battler, taking out their Pokémon easily. Jessie and James's attempts to put Snorlax to sleep through deceit and hypnosis, resulted in Snorlax sending them blasting off with a Mega Kick but gave Ash and his friends the idea to lure Jigglypuff out to Sing Snorlax to sleep. The plan succeeded and eventually managed to stop the Snorlax. This gave Ash and Pikachu the perfect opportunity to weaken it with Thunder and capture it while it was asleep.

Ash kept Snorlax on his team for the remainder of his time in the Orange Islands, but could not use it in the Orange League finals because it would not wake up and needed to be switched with one of Ash's Tauros. After the tournament was won, Ash then decided to keep his Snorlax at Professor Oak's Laboratory permanently because he could no longer feed it and only called upon its power in major battles.

Ash called Snorlax in Kanto Battle Frontier and also in Diamond and Pearl

5. Charizard

Charizard

Win rate 73%

Charmander originally belonged to a boastful Trainer named Damian. However, in Charmander - The Stray Pokémon, Damian grew tired of Charmander being weak, and so he abandoned him, leaving him on a rocky outcrop and telling him that he would come back later. Charmander's health deteriorated, but he was able to resist capture by Ash twice before explaining to Pikachu that he was waiting for Damian. Later, Ash met Damian and learned that he never planned to return for Charmander. Outraged but mostly concerned for Charmander, who was now stuck out in the rain loyally awaiting Damian, Brock, Ash, and Misty rushed to his rescue, with Brock carrying him to the Pokémon Center while Ash sheltered the little remaining tail flame with his coat.

Despite the care shown to him, Charmander was unwilling to remain at the Pokémon Center and returned to the rock where he had been staying. However, he came across Team Rocket, who had stolen Pikachu. Charmander ordered them to return Pikachu, and when they ignored him, he blasted them with Flamethrower to send them running away, leaving behind Pikachu. Ash invited Charmander to join them, but Damian turned up with a bunch of Poké Balls and said that he had abandoned Charmander on purpose to toughen him up. Damian threw a Poké Ball at him, but Charmander deflected the Ball in defiance. Having seen Damian's character, Charmander staunchly refused to return, and when Damian threatened to crush him with all of his other Pokémon, he attacked Damian with a Flamethrower attack alongside Pikachu, who used Thunder Shock. Damian fled and Charmander happily joined Ash's team instead.

Charmander became Ash's main pokemon but later when he evolves his personality changed and when he finally evolved into Charizard he started disobeying, Ash. Although Charizard didn't flow Ash's orders he was extremely powerful and one of Ash's most powerful pokemon.

4. Krookodile 

Win rate 75%

Krookodile debuted in A Sandile Gusher of Change! as a wild Sandile, where he was revealed to be the leader of a group of other Sandile who lived near a local spa resort. He and the group caused trouble at the spa resort on Route 1 to get the owners' attention. He was actually trying to save the other Pokémon in the area because he knew that a geyser would soon erupt. With the help of Ash, Iris, and the son of the spa resort owner, Dan, Sandile was able to save the Pokémon. In the end, Sandile was shown to have gained respect for Ash and began to follow him.

Sandile wanted to defeat Pikachu, so he fought him multiple times but lost, but Krokorok returned at the end of Explorers of the Hero's Ruin! to defeat Pikachu in battle. In the following episode, he battled against Pikachu and ended up causing the two of them to go flying. He was later found by Ash and helped them locate Pikachu. It was revealed that Krokorok had followed them through various locations, including Nimbasa Town and Nimbasa City, to have a rematch with Pikachu. He also followed them through Chargestone Cave, where he was shown to be the cause of a pen being stuck in the Klinklang in Evolution Exchange Excitement!. Krokorok later allowed Ash to use him to help Mick learn to battle, and he eventually teamed up with Pikachu under Mick's command in a Double Battle against Sean's father's Seismitoad and Scolipede, where the duo eventually won. Krokorok then got the chance to battle Pikachu like he had wanted for so long, and after a hard-fought battle, Pikachu emerged victoriously. Krokorok was depressed by the loss and begun to leave when Ash invited him to join their team. Krokorok happily agreed and was caught by Ash in a Poké Ball.

3. Ash-Greninja

Win rate 77%

Froakie was introduced to Professor Oak, who was fascinated by the Bubble Frog Pokémon. For most of the subsequent trip on Route 4, Froakie was seen outside of its Poké Ball. After a wild Fletchling took a Berry that Bonnie was going to give to a Dedenne, Froakie stubbornly attempted to fight Fletchling, only to lose. After Ash learned that it was only trying to get payback at Fletchling for making Bonnie sad, he and Froakie challenged Fletchling to one final battle by climbing the rocks to match Fletchling's speed. Although Fletchling escaped from Ash's Poké Ball once, Froakie later defeated it, which ended in both its defeat and catch.

Ash's Greninja was one of my favorite pokemon, Shortly after evolving into Greninja, through its strong bond with Ash, he can call upon a transformation similar to Mega Evolution, where it takes on an appearance resembling its Trainer while being covered in a water veil. In its final form, the water veil moves from around its body to its back and forms an "X" shape, which resembles wings, then the wings form into a small sphere shape of water on the middle of its back with a light blue ring in the middle of it and it then grows in size until it forms into a giant shuriken made of water. Its full capabilities were unknown, but it appears to give a significant boost in speed and power. In its completed form, it can rival the power of Mega Evolved Pokémon. Ash-Greninja shows the bond between Ash and his pokemon.

2. Kingler

Win rate 80%

Ash originally obtained Kingler as a Krabby in Mystery at the Lighthouse, when he became angry at Misty for saying that it was a fluke that he caught all his other Pokémon. Storming down to the beach, he discovered a minuscule Krabby and made fun of it. Krabby challenged Ash, who fought it with a nearby stick and then captured it in a Poké Ball. Having six Pokémon already in his party at the time, the newly caught Krabby's Poké Ball was immediately teleported away, much to Ash's surprise and concern. He soon learned that Krabby was sent to Professor Oak.

Ash's Kingler was the sixth Pokémon he caught in the Kanto Region and his seventh overall. It was also the first of Ash's Pokémon to primarily reside at Professor Oak's Laboratory in Pallet Town. Kingler is Ash's only Pokémon to win in a Pokémon League match single-handedly, excluding one-on-one matches.

1. Blaze-Infernape

Win rate 85%

Chimchar was originally Paul's pokemon, Paul saw Chimchar being chased by a group of wild Zangoose. The situation looked bad for Chimchar, but he pulled off an extremely powerful Flame Wheel in his stress. This impressed Paul enough to add Chimchar to his regular team. However, this first impression did not match up with Chimchar's normal abilities, resulting in Paul criticizing him for being weak. Since then, Paul has been pushing Chimchar to the limit to duplicate the amazing power he saw before. Traumatized, Chimchar gained a morbid fear of all Zangoose.

After losing to Cynthia's Garchomp in Top-Down Training, Paul realized that Chimchar was not fulfilling his expectations. This culminated in the Hearthome City Tag Battle Competition in Glory Blaze!, where he was forced to battle alongside Ash. That night, Ash discovered Paul's training regime, which involved his Pokémon attacking Chimchar in the hopes of recreating the power he had seen before. Ash intervened and took Chimchar to the Pokémon Center where Nurse Joy told Paul he would be unable to battle. Paul ignored this warning. During the next battle against a Zangoose and a Metagross, Chimchar was too scared to make any attack when caught in Zangoose's claws and had to be saved by Turtwig, who was seriously injured as a result. Chimchar made up for this by protecting Turtwig from a Fire Blast attack. Realizing that not even reliving the traumatic event of being attacked by Zangoose could motivate Chimchar to do Blaze, Paul gave up on the Chimp Pokémon. For the remainder of the battle, Paul refused to give Chimchar any orders. Consequently, Ash gave Chimchar commands from then on, and the three soon won the battle. After the battle, Paul released Chimchar before Ash and his friends arrived on the scene as they realized what happened. As the little Pokémon headed back to the wild, Ash invited him to join him, to which he accepted. Paul rudely commented that the two were perfect for each other: both were pathetic.

Later with Ash Chimchar evolved and became very powerfully in fact he was the strongest pokemon Ash had in the Sinnoh region.

In the new season of Pokemon (Pokemon 2019) ash has a super strong team, this team might be one of his best teams yet. I didn't include any of those because the season is still airing 

Reference source https://bulbagarden.net/