Every time I think about it, I bring up the Game Marketplace and hit the Indie Games, and its New Arrivals. It seems like there is a new game every day there.
Just tonite, I downloaded free trials of Platypus, A Killer's Dream, and Neo Terra. They looked interesting, and a trial is a no-brainer. The games are inexpensive, if I end up buying the full version.
And yes, as I mentioned the other day, my download of Armor Valley turn out interesting enough, that I dropped the few dollars to purchase the full game.
(and I'm still playing through Sacred 2: Fallen Angel, but that's a post for another day)