Midnight Synergy (Wonderland series) has compiled a selection of 10 freeware games released in 2007, complete with proper descriptions and download links. Definitely worth a gander or two.

Meanwhile, an unofficial Grand Theft Auto IV web site had also posted a list of top 20 free games of 2007, though this article is done with poor judgment as more than half of the titles included were either released in 2006 or before that. There is also at least one game that comes with the Starforce protection - proceed with extreme caution, or avoid entirely.