Oh that was a great fight! I forgot about it until you mentioned it. MEDUSA FIGHTS ICARUS ANGELS/ICARUS FIGHTS MEDUSA ANGELS ftw.

I always think of size when it comes to epic boss battles, and for me, none stick out more than Stallord from Twilight Princess

It's hard to get an idea from that picture, but one of his vertebrae is as big as you:

The dude's massive, and the battle itself is pretty awesome as well.

Ganondorf from Ocarina Of Time is my answer.

Andross in StarFox 64

Ganon in OOT and in TP

Majora's Mask final boss battle.

Incredible and incomparable.

Of Myths and Monsters had an awesome final battle, thanks for reminding me! Then again, I'm a sucker for games where you can fly in the final battle.

How about bowser in NSMBWii? That reptile seriously had me on my toes.

Oh, and the long stairway before you meet Ganon in OOT...the music....it just added to the epicness of the battle!!

The boss in TP, where you have to fight with the spinner, can't remember his name though.

I agree with everyone who said Ganon in Ocarina of Time.

The music, lighting, mood and everything is perfect. It's my favourite boss ever.