Game-download service Direct2Drive is celebrating its 5-year anniversary by offering a large selection of games (all for PC) for $5 each. My top pick: BioShock, one of my all-time favorites.
It's primarily a first-person sci-fi shooter, but with pivotal role-playing elements that fit perfectly into the story. I won't spoil one bit of that story, but I will say it's compelling enough to keep you playing all the way until the surprising, unpredictable, utterly satisfying end.
It's also genuinely scary in places. I actually yelped a couple times while playing.
Granted, BioShock is a couple years old, as are most of the $5 titles--but there's still plenty of great gaming to be had. Other choices include The Chronicles of Riddick: Assault on Dark Athena, S.T.A.L.K.E.R.: Shadow of Chernobyl, Max Payne 2, and MLB 2K9.
I haven't tried Direct2Drive myself (yet), but I'm definitely planning to pick up a couple of these gems. If you've had any experience with the service, or you have some opinions to share on any of the games, hit the comments!