Title says all. What are your favorite battle theme tracks from video games? Personally, I have three. They are...
Final Destination (Super Smash Bros. Brawl)
Out of all the tracks used in the Smash Bros. series this track tops my absolute favorite list with Gourmet Race (also from Brawl used on Meta Knight's stage). The fast pace of the track really fits well with the tension you get for going all out on a stage with no obstacles and flying through space and time. I'm very glad they brought it back for the Wii U version of Smash 4, though I wish they also used it in the 3DS version.
Shadow Queen Final Battle 2 (Paper Mario The Thousand-Year Door)
This is definitely one of the boss tracks that greatly fits with the theme of the fight, especially since you're fighting a demon queen for the fate of the whole world. Considering how freaken evil she is and the fact that beforehand you flat out couldn't so much as make her tickle really says something about her. The best part? Unlike the other final bosses in the Paper Mario series she's relying on her own power, not some enchanted weapon or evil heart for a power-up. Bowser could learn a couple of things from her.
The Mysterious Figure (Kingdom Hearts Birth by Sleep)
I swear this is perhaps one of the freaken best boss themes in the entire Kingdom Hearts series, especially considering this Bonus Boss can AND WILL one shot you unless you come prepared. At that point, it just takes a couple of hits depending on what moves/combos he's using. This boss fight literally makes Sephiroth's fights look like child's play, and that's saying something. He can heal himself while blocking your attacks, perform loads of fast and powerful combos, is capable of KNOCKING YOUR SKILLS/MAGIC OUT OF YOUR SLOT MENU forcing you to recover them, can cancel your basic combos by MAKING TIME GO IN REVERSE AND PREVENTING IT FROM HAPPENING WHILE NEGATING THE DAMAGE, and is capable of making clones of himself that will CAUSE THE GAME TO LAG if you play the PSP version. Seriously the only thing that kept me from rage quitting and breaking my PSP on accident was the fact that this fight gives us this freaken awesome track.