Brink didn't get great reviews when it launched or garner much praise but today it went free to play on Steam. If you are looking for a free multiplayer shooter to play that offers interesting character customization, parkour gameplay mechanics and a bit more... the price is right. If you want you can still pickup the games DLC but the base game is entirely free and right now there are quite a few people playing it on Steam so if you do try it out, you won't be the only one playing.
http://store.steampowered.com/app/22350/BRINK/
http://store.steampowered.com/app/22350/BRINK/