hm i can't think well, but heres a couple
movies:
Cowboy Bebop: Knockin' on Heaven's Door - the fight where spike has the broomstick, definately some good kungfu movie influence there
End of Evangelion - asuka vs the units.. yes, there was a lot, but the physics and everything in this fight was just so cool
series:
Naruto - Gaara vs Rock Lee ofcourse, everyones fav.. my take on it is just how they set up this amazing character Gaara to be this unscratched monster who doesnt even flinch.. then lee takes off the weights, and gaara is suddenly ****ting himself.. brilliant
Naruto - Sasuke vs Orochimaru, most people will agree this is the 2nd best fight in naruto.. and though oro didn't even fight close to full power, it was a fun fight
Trigun - Vash vs Knives.. brilliant
FullMetal Alchemist - Edward Elric vs Greed... something about how fluently animated this fight was.. so cool
and DBZ related heh.. i dunno, there weren't too many "amazing" fights, i did like when kid buu beat the crap out of vegeta though, that was pretty gorey.. and when videl got beat up.. hmm.. but bebi in GT had a decent fight against vegeta too, but i only saw it in AMV so..