http://www.kongregate.com/games/rikfuzz/booty-callLittle game I made in 48 hours with my ex gf, I did everything except the character illustrations, but concept / dialogue stuff was a joint effort.
http://hotpengu.in/polyko.htmlLittle game made in a week or so, also with my ex as a friend's birthday present. I did all the pixel stuff, she did the intro/complete illustrations and voice sample. A ton of stuff is somewhat based off the birthday boy's work too, inc the guitar samples. Senile Team even made a dreamcast port. This game's a super simple find-and-collect-em-up platformer, but very important to me, and kick started my current platform game project.
http://dl.dropbox.com/u/1534394/rocketbike.exeWindows only there.. A hard little game, my first 48hr game.
http://www.kongregate.com/games/zworp/umag2Scorched Earth / worms / multiplayer artillery type game. All graphics and sound. I'm sorry about the lobby UI.
http://www.miniclip.com/games/robo-pop/en/Little Pang clone, I did graphics music and audio for.
That's all I can find that's free and floating around online! A few others I only did audio or level design stuff, but I assume that's not in the spirit of the thread?