Game Music Bundle
is a pay-what-you-want promotion for 5+ game soundtracks:
2. Plants vs. Zombies
5. Frozen Synapse
If you pay $10 or more then you get an additional 10 albums.
Downloads are DRM-free 320kbps MP3s. Play the music anywhere, anyhow you want — no hassle, guaranteed. If you pay $10 or more, you'll also receive links to FLACs.
Of all the games listed on that page, I've only played Terraria, Plants vs. Zombies, and Frozen Synapse. Of course musical tastes are a matter of opinion but I think you'd definitely get your money's worth from those three alone. I already own the Frozen Synapse soundtrack it is a really good listen even if you didn't have any experience with the game its from.