Sectorgame

Personally, I'd have to go for Bastion, which distinguishes itself through its audio IMO - a sort of mix of fantasy and western that in places reminds me more than a little of Firefly.

Homeworld's still got it locked down, to be honest.

I know it's cliche to say so, but I honestly think Chrono Trigger might get my vote, at least out of what I've played.

I dunno about the whole game in general, but I still love the title theme of both original Descent games.

Hard to say. There have been so many over the years. Freespace and Descent all had good soundtracks. Mass Effect's soundtrack is probably one of my favourites from more recent years.

Super Probotector, SNES. Maybe....