There are only two things I'm going to recommend out of today's batch, but they're both quite solid.
Fallout: New Vegas: $4.99 - A nice combining of the new and the old from Fallout. The game uses the perspective and engine of Fallout 3, but takes place back in the western US and a lot of the original creative team from the first couple of games worked on it. Not quite as good as Fallout 3 in my estimation, but still an absolutely fantastic game.
SpaceChem: $2.49 - This game is, as a friend of mine on Steam observed, more about programming than chemistry, and it gets brain-meltingly hard, but it's really, really, REALLY good. It's also one of the most original puzzle games I have ever seen. For the price, it's absolutely worth it.
What I'm getting: Still deciding. Probably Universe Sandbox and the Fallout: New Vegas DLC, but not sure yet.