Now for me (in no particular order):
Super Smash Bros. Brawl OST (Because it has just about every song that Nintendo ever made and they're all orchestrated and/or kept in their original versions beautifully.)
Metal Gear Solid 3 OST (When I played MGS3, it was the first time that I actually listened to the soundtrack while playing a game. And that Snake Eater song is EPIC.)
Halo 1+2+3 OST (Because, well, it's Halo. The games always had a kick-ass soundtrack.)
No More Heroes OST (Same reason as Halo. Kick-ass soundtrack.)
Street Fighter III 3rd Strike OST (Personally, this is my favorite because it had some of the best stage music I've ever heard. Then the way Hideki Okugawa produces and the way INFINITE raps pretty much sealed the deal.)
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Quote from Klapzi
The cool part is that I never get tired of being deceived
Quote from tactics
Just because someone's head was chopped off doesn't mean they're dead. That's just silly.