Naruto:
Naruto vs. Sasuke
Rock Lee vs. Garra
Sasuke vs. Itachi
Bleach:
Ichigo vs. Byakuya
Full Metal Alchemist:
everything
G Gundam:
Everything
One Piece:
The whole freakin war Arc
any fight with Zoro :p
Dragonball z
Gohan vs. Cell
Majin Vegeta vs Goku
Goku Vs. Baby Vegeta