1. Exile, Vilivy - Portal 2
It's made by an indie rock band The National, well most of us know it. The music and the lyrics got me, it's just simply good. With a simple mix of sound and slow lyrics. They also place the soundtrack on a good moment of the game.
2. Titus theme - Warhammer 40000 Space Marine
Titus is one of good character build in a story of Warhammer, and this theme that was used on the main menu of the game was also quite enjoyable to be listened.
3. Lone Wolf - Halo Reach
This is the first track I heard from the Halo: Reach trailer which was developed by Bungie. This music very suit the "Lone Wolf" personality they want to make to the main character, which also has a same nickname.
4. Metro Last Light theme song
Well this one is a bit too fast, but still good to hear. They mixed it with some other background environmental music on the main menu.