Kimmo vs Paul Varlens when Kimmo dropped weight from 250 down to 200 and shaved his head, Varlens weighed like 360 lbs (it's been a long time since I have seen that fight but I remember it sticking in my head as a great fight and I am not a Kimmo fan at all).
Severn vs Oleg, the brutal knees to the face were great as you could see the one that opened him up and then Severn continued to drop knees, it was a bloody mess.
Fedor vs Herring, such a dominant performance and the turning point of fedor's career, Herring's face was battered and his left eye was fugged up really badly.
Couture vs Rizzo, what a war that was as at one point it looked like Couture had the fight won and then the following round Rizzo unloads those leg kicks and it looked like Couture was gong to fall. Honestly that is probably the #1 or #2 fight of all time.
Fedor vs Fujita. Getting crushed with a right hand, doing the fish dance and holding on, regaining his legs and then delivering that insane combo to end the fight. Liver kick, left hook, right hook, rear naked choke. That was one of the best finishes ever I've ever seen in MMA.