There are also the free bundles (
http://www.thefreebundle.com/) which don't really expire (there are more recent ones but so far as I can tell you can download from any of them). The games are.. What you'd expect for the price, but if they even give you twenty minutes of fun they are worth it. I haven't played nearly all of them but Antibody is pretty fun.
I bought the Indie Bundle Jam 7 a short while ago, haven't had time to try out all the games yet.
Planets Under Attack is a fun little game, it's a little twist on tower defense, has easy to pick up and play mechanics and really good aesthetics. It's also, for me at least, surprisingly difficult. That said, it's not really that deep and I doubt it will have much staying power.
Ion Assault is an arcade-like space shooter which is (as they say) like asteroids on steroids. Like asteroids your goal in each level is to destroy all the asteroids (which split into smaller and smaller pieces) while destroying/avoiding enemy spaceships and the like. I had a good time with it, the aesthetic is nice, the controls are pretty good, and it's just fun. That said it's pretty short (five levels I think) but then it costs like a buck.
I haven't really tried the others yet, installed and started Two Worlds II and so far it felt pretty "Meh" to me, I figure I'll give it a little bit more time to see if it grabs me but have in the past decided there are too many great games out there to waste my time on 'ok' ones.
I may buy the bitcoin bundle, amazingly I don't have world of Goo yet (it's one of those games I keep meaning to buy but never getting around to it).
I'm curious about Dungeons.. I remember the debacle of it's release and how it was touted (by possible them and certainly the fans) that it was going to be the spiritual successor of Dungeon Keeper and failing (spectacularly) to live up to that.. However how is it as a game? It's hard to get a clear review on it given how many boil down to "It's not Dungeon Keeper 3!1!1!!"