I have a large amount of favorites, honestly. For starters, I'll cut out the ones from games I haven't actually played;
Dungeon Siege's Theme Song
by Jeremy Soule
This version, of course, is a fan remake, but it honestly makes it better while still very much being the same song but with a lot less orchestra.
This song represents perhaps a huge part of who I am and goes back to when I was a child. it was my favorite from the game and heavily encapsulates the theme of action and adventure within the game.
The Elder Scroll's V: Skyrim's Dovahkiin
by Jeremy Soule
What hasn't already been said about it? To be perfectly honest, all of the last three Elder Scrolls had absolutely stunning openings, and I feel they're actually best chained together, but this one does stick out the most to me. Who knows. Maybe the sixth will be even better?
Final Fantasy VIII's Liberi Fatali
by Nobuo Uematsu
An eerie, beautiful and sweeping song. Not much to really say or mention other than it basically being the sheer epicness of the Final Fantasy series, especially past the sixth main entry.
Final Fantasy VII's One Winged Angel
by Nobuo Uematsu
Yet another entree from Final Fantasy. More or less the same, but moreso on the action aspect of Final Fantasy. I think I have a think for Latin.
Pokemon Black/White's N's Farewell
by Junichi Masuda
A sad song. a good character, and a very emotional song.
Pokemon Gold/Silver/Crystal/HeartGold/SoulSilver's Dark Cave
by Junichi Masuda
Honestly, I like both the original and remake. I used to only like the original, but I've since grown to look past the changes and recognize that it's just as heavy and simple. It's straight to the point.
Pokemon Gold/Silver/Crystal's Champion Theme
by Junichi Masuda
To be honest, my favorite version BY FAR is a fan remake, but I decided I'd try not to use too many covers and instead put my preferred official version.
Half-Life 2's Triage of Dawn
by Kelly Bailey
s'beautiful. s'awesome. s'good.
aaand last but not least.
DOOM's At Doom's Gate
by Robert Prince
BECAUSE IT'S DOOM!