Here's another website that's all about entering free giveaways for games, though this one is hosted by the folks behind the Indie Gala bundles, so those of you that were hesitant to trust my Steamgifts article (though I dunno why you wouldn't) need not fear their keys being logged.
The premise behind the site is pretty much identical to Steamgifts, you generate points over time as people submit their games and you then use those points to enter these giveaways for a chance to win a game. The difference here is that Gala Giveaways carries games for Desura as well as Steam, and as far as I know they don't have a minimum Steam account value necessary to sign up, though don't quote me on that.
Admittedly, I don't use Gala Giveaways as much as the other sites of it's kind, but that's mainly because the website always seems to load extremely slowly for me. This could be entirely because of my Canadian interwebs though, so judge for yourself. I've only won a few games from them, but when I have it's always been straightforward and I've never been jerked around (as I have been with another site I'll cover in a later update).
What I won:
Red Faction: Guerilla
Indie Game: The Movie
You can find the site over here: http://www.galagiveaways.com/home