Ash vs Paul @ Lake Acuity because I enjoyed how strategical Paul was in that battle and just pretty much murdered Ash.The guy trained harder and had better preparation for this upcoming full battle.Examples of his genius battling would be constantly switching out his pokemon against Ash,each pokemon Paul brought out was a difficult challenge excluding Weavile.Weavile was the weakest pokemon in Paul's lineup during that battle,the only noticable improvements it made was it's increase in speed as it was able to succesfully dodge an incoming Staraptor and then land on it's back for an attack but despite that it lost to Staraptor in the end.
Paul used Electabuzz's status move Light Screen as a way to cover up for his other pokemon,he cleverly returned Electabuzz after using Light Screen then sent out his Honchkrow,when Grotle attacked Honchkrow Light Screen appeared to reduce the damage,Paul used this same strategy with his Torterra later on in the battle.
His Ursaring was an absolute monster in this battle and this is truly when it became a true powerhouse.Paul didn't use Light Screen for Ursaring at all and it didn't really need it but it would have helped.Paul had Ursaring use the status move Bulk Up to increase it's attack/defense powers so all it was doing was pretty much attacking,counter-attacking,and taking hits.
It all paid off as it just bulldozed through half of Ash's team,when it went up against Pikachu it got paralyzed and it's ability Guts activated which increased it's attack power,Ash commanded Pikachu to use Thunder Bolt on it but it did little good to Ursaring as it just pretty much ignored the damage and just finished Pikachu off with a Hammer Arm.
So overall I'd give this battle a 8/10