Hmm.. found a couple of games I haven't heard of before.
But I'm tired of seeing FEAR Combat, TM Nations and America's Army in such lists. They're not free in spirit. Cut versions of popular commercial games and promo action for army service... that's boring stuff. That's why I read IG - you can find all sorts of genuine crazy creativity here...
http://www.trackmanianations.com/ , btw. Not sure why it isn't linked in the post. Great game, one of last year's best releases (counting both free and commercial games).