From Stardock ( http://www.impulsedriven.com/ ):
Titan Quest (like Diablo), Defender of the Crown (classic), and Dawn of War: Dark Crusade (Warhammer 40k) are each $4. I picked up the next one in the 40K series a couple weeks ago off Steam and it's fun; reviewers dinged it for being too similar to this one.
From GoGamer ( http://www.gogamer.com ):
A fistful of games each under $10 including Medieval II, Supreme Commander, The Guild 2, Half-Life 2, and Starsiege Universe.
And Steam has all the Ghost Recon games for $20. Gah, the first one was pretty tense and here's 5 of 'em.
