|Heroes of Newerth|
Steam for Linux, THQ Support, Humble Packs and this list going on growing greatly.
If you are a fan of DOTA and League of Legends, you must try Heroes of Newerth on your Linux. It's totally free to play!
I won't talk too much about this. It's really a high quality game and I can guarantee you, you will enjoy while playing HoN.
Heroes of Newerth Official