Here is a quick screen shot I took last night to show the games I've currently been playing the most. Not really a scientific breakdown or anything, but of the 20 or 30 games I've downloaded, these are the only ones I've actually been playing:
NES emulator (via Installer)
Subway (can't find the phobos address for this puzzle game).
Now that I've typed these all out, I realize I don't even play that many of these games. None of the $10 games were really worth the money. I'd say the pricing on most games is %40 over what it should be (ie, Enigmo, Galcon, Spore, and South Park are close to $6 games... Toybot should have been $3).
By far the best game for the money is Mote-M. This desktop tower of defense game is a total steal at $1!
Toy Bot Diaries Free is also worth the download since it includes new art and levels that don't appear on the full retail version.