There's nothing better than a great final boss theme that just gets you pumped and ready for battle. What are some of your favorites? There are so many that I love, it's hard to choose. Rebuilding Ourselves from Eternal Sonata is definitely top tier...especially since I adore Chopin's music anyway and it's an epic orchestrated remix of his Revolutionary etude. Another one that I love is Howl of the Departed from Lost Odyssey. Uematsu always has...interesting final boss themes, and this one just takes the cake for being over-the-top.
My favourites are Bowser from Yoshi's Island and Last Battle! (VS. Champion) from Pokemon Gold/Silver (or HeartGold/SoulSilver).
I have a few favourites and they're all fairly different. First off, The Final Battle from Banjo-Kazooie by Grant Kirkhope. An epic version of "Teddy Bears' Picnic". Grunty's theme, Banjo's theme, and a bit of Tooty's theme all intertwined with a kickass rendition of the overworld theme and general awesomeness. King Dedede's Theme from Kirby's Dream Land by Jun Ishikawa is instantly recognizable from just the opening static hum. I never owned this game as a child, but I would play my cousin's copy whenever I could to make it to the end, hear the music, unlock the sound test and listen to it on repeat. Last Battle! (VS. Champion) from Pokémon Generation II by Junichi Masuda. I just think it's the most... Pokémony battle music. Before Super Mario Sunshine happened, Bowser was a badass. And the aptly named Bowser from Yoshi's Island by Koji Kondo is proof that Bowser was born a badass - it's Baby Bowser's theme. The music is like no other piece in the game which is all music box in style and it is amazing. Kondo tends to like jazz, bluegrass, and calypso in his Mario compositions and out of nowhere came this great rock gem. Continuing with Bowser... is Ultimate Bowser from Super Mario 64 by Koji Kondo. As a child the epicness of the music with the organ, combined with the oddly miscoloured (badly bruised?) Bowser in this battle just made it a fight for the ages. But when it comes to epic final boss music there is only one claim to the title, Dancing Mad from Final Fantasy VI by Nobuo Uematsu. And operatic medley of themes from the game, this behemoth clocks in at almost 18 minutes! I haven't played the game, but that must have been one hell of a boss battle.
(Warning: A lot of Xenosaga fangirling here. Don't blame me, the game has great music xD). One of my top favorites is the Xenosaga I final boss theme. When I got to that point where I was about to kill the final boss, I got kinda sad, because the theme was just so awesome that I just wanted to let the game idle and just listen to how awesome it is...I dunno, there's just something about it that makes it awesome. xD; Aaaand another great boss theme is Xenosaga II's "major boss" theme(not a final boss one but definitely good enough to probably qualify for one! There's also the minor boss battle theme that's pretty cool, too). Also! Before I forget, WIld Arms 5 final boss theme(can't find it on youtube/too difficult to find and it's a lot of effrot) gets an honorable mention because of the lyrics. Even though it's japanese, they fit so well with the whole final boss situation kinda. ^^; But yeah, those are my favorites!