I don't know, the best anime fight ever for me has got to be Goku vs baby.
Since i don't remember any fight that left an impression to me like that one did.
for actually fights i gotta say either the fight between naruto and sasuke at the waterfall with the two statues or the one between lee and the guy that uses his bones to fight(loved the drunk fighting part).
Now, I know this isn't considered anime, but since it features video game characters (animation of sorts), I had to mention this.
By the great and almighty Monty Oum:
1. Haloid
2. Dead Fantasy II
3. Dead Fantasy I
4. Icarus
5. Road II
6. Road I
Now onto anime, Grenadier had some really awesome gun duels. I suppose Air Gear also had some great duels as well. All Yu Yu Hakusho fights were terrific and suspenseful, and I gotta agree with Samurai Champloo and Tenjou Tenge. History's Strongest Disciple Kenichi was a corny show, but the kung-fu moves depicted are no joke and the fights were great in my opinion.
And if anyone read the manga "Flame of Recca", you will know what it means to be badass while fighting. Same goes for Black Cat manga - the fights were awesome. (The anime of these two series plunked. Seriously.)
Gundam : Char's Counterattack. Amuro vs Char in their final battle. :D
in the end,the Axis Meteor can be prevented by pushing it with his Gundam :shock: