There are several battles I'd like to have seen. Note:all would be full battles.
Misty vs. Dawn-I'd hoped the 2 would meet and battle in DP at some point since Dawn seemed kind of interested in her, but that never happened so I'd like to see them battle. I think Misty would probably win.
Gary vs. Paul-The 2 most powerful, badass rivals. I'd think the battle could go either way depending of which Pokemon each uses, but I'd hope Gary would win.
Ash vs. Trip-I was so dissapointed when the leauge battle for these 2 was just a 1-on-1 preliminary match. I'd love to see how Trip's other Pokemon minus Serperior and Conkledurr have improved since last seeing them. Obviously I'd want Ash to win.
Ash vs. Virgil-First of all I'd love to see an Eeveelution full battle. Second of all I want to see Virgil in a battle lasting longer than a minute to see how strong he really is. I'd hope Virgil would win.
Virgil vs. Cameron-Pretty much the same reason as above with Virgil winning.