let's see if i can remember them all
Squall vs Seifer
Phoenix vs Edgeworth
Mega Man X vs Zero
Captain vs CATS
Tifa vs Aeris
Mario vs Sonic
Jim Raynor vs Sarah Kerrigan
Mega Man vs Proto Man
Battler vs Beatrice
Ryu vs Ken
Cecil vs Kain
Alucard vs Dracula
Disease vs Madagascar
Link vs Dark Link
Samus vs Ridley
I think that's right... 1 of the last 3 might have been Cloud vs Sephy