LOL, its fun how this thread is full of spoilers... by the way, how do you wrap something as spoiler?

Well, I was thinking about Kenshin but everyone has mentioned it, so here are others:

From SAMURAI 7 (the anime series of course) the first fight between Kambei and Kyuzo is just awesome, full of action and speed. And of course the last fight, that begins just after Katsushiro deflects the bullet of the robot... man, those fight really turn you on.

From Basilisk (Kouga Ninpou Chou) on the first episode, between Shogen and Yashamaru is amazing, it really gets you into the story. The animation is of the greatest quality, I don't remember the exact number of frames it took to make the first episode, but once I read it was many times more than the average.

Both series are full of action and great fighting scenes, if you have the chance to see them, don't hesitate.

I agree with most of the ones posted before; here's a few that haven't been mentioned yet:

JoJo's Bizarre Adventure


Noir


Elfen Lied

A few people have already mentioned the battle in One Piece against Luffy and Crocodile. I'm here to reiterate their claims. I caught the battle myself a couple of weeks ago, and promptly rewatched it several times.

I always enjoy the fights where the hero is the underdog, and manages to overcome an opponent that he should have no chance whatsoever of defeating. Such is the case here. This one clip doesn't do the fight real justice, since you have to watch the entire arc to appreciate the emotions and tension that this fight represents, in which hundreds of thousands of lives rest in the outcome of this fight, but newbies should find it to be an enjoyable clip nontheless.



The bar has been significantly raised here. If Luffy has a better fight later on, I'll be quite impressed.

By the way, if anyone has an mp3 of the classical piece played, please share it, thanks.

The music in that scene is from Dvorak's New World Symphony.

http://www.megaupload.com/?d=E0MKN5V9

Enjoy

I agree with the final showdown between Dio and JoJo. EPIC sums it up perfectly and you could see the writer put a lot of thought into it with all the characters actually thinking their moves through instead of random DBZ flurry of punches and junk.

It's not much of an actual fight but in EP 4 of DIEBUSTER:


EP 5 of Gunbuster

Wow. Let's see if I can pick out any fights from animes which haven't been mentioned yet here but should definitely be..

Mech Battles:

Gun X Sword:
The build up to that fight was great as well as the overall animation and even the music was pretty fitting. Come to think of it, that anime was full of awesome mech battles. True, some were too short but the animation was always awesome and the music nicely complimented it.

Power Battles:

X TV:
All fights in this series were awesome but of course the fight of was epic as long as your not sick of the repetitive music by that time.

Noein - Mou Hitori no Kimi e:
The fight between It has a unique animation style very fitting for fighting sequences.


I find it strange that I can only remember one epic mech battle ..aside from the ones already mentioned. Thanks to those who mentioned Macross Plus though, I've been planning on watching thpse OVAs for a while now. The Macross movie kind of turned me off.. but now I've got a good reason to watch it.

the fight between Kenshin and that guy who claimed himself to be the Son of God was awesome. the anime turned widescreen just for the fight! :D

also i like all the fights from Tokyo Majin Gakuen Kenpuchou. they're fricken cool!! :D

Noein



Edit: Oh, just saw this was already mentioned. Seconding it anyway, it was an amazing sequence.

T_T Someone already mentioned the One Piece fight I was thinking about... Well, it was amazing xD However...



Another fight I loved was from Shoujo Kakumei Utena (Yeah, not the anime most of you would expect to see here)



Gankutsuou



And last but not least, probably every single battle scene in Eureka Seven. Mechas surfing in the sky AND fighting at the same time? That show is too amazing for it's own good @_@;;;