Galbadia Hotel
Just click the "view all" link, scroll through the list, and when you've regained consciousness, have a closer look at it again. These are currently over 6'500 game soundtracks in MP3-format, either ripped directly from the games or from official soundtrack CDs. All the files are available as free, direct downloads - no registration needed. It's regularly updated, too (there's a newsletter which will keep you informed).
There's also a forum with user-uploaded albums, game commercials etc.
Edit: Oops, I thought this board was to "suggest other sites", but I guess it's more meant as "suggestions four our site"
sorry!