I didn't have the biggest budget for these sales, and I think I could have done better but here is what I got:

Amazon.

Binary Domain - $10 (75% off)

Borderlands GOTY - $7.50 (75% off, to play with friends)

Burnout Paradise: TUB - $5 (75% off, rebuy due to sold PS3 version)

Steam

Star Wars: Knights of the Old Republic - $2.50 (75% off, friend recommendation)

The Witcher 2: Enhanced Edition - $15.99 (60% off, nuff said)