Every Wednesday until the end of the month they have a new bunch of games for only $6 each. It's already up to week 2, and this week they have Crayon Physics which is a great kids game. Direct2drive haven't been as good lately, so it might be worth keeping an eye on these specials.
As is usual, watch out for region restrictions, for example Sid Meiers Pirates! would be a good deal but no good for OZ!
They do have "King's Bounty: Armored Princess" for USD6, which is pretty good. Not sure if the other prices are bargains compared to Steam's specials.