Not much of a fan of video game music, but I got a couple favorites. Everything from Silent Hill 1 and 2 Portal: Still Alive Street Fighter 3: 3rd Strike, Snowland Dawn of War: Winter Assault, Imperial Guard theme Halo 1 Banjo Kazooie
I don't consider beating a game until I've beaten it at it's hardest difficulty (if there are such settings). I've beaten a few, but not as much as you guys have.