Also, the very creative and entertaining indie first-person brawler Zeno Clash is dirt cheap as well.
Meanwhile at GOG.com, The Guild and Spellforce Platinum come at the extra-cheap set price of USD 13.99 instead of 18.90 (or something) for the whole weekend.
If you like good deals, this combination gives you a whole bunch great games from diverse genres. Go grab them!
Disclaimer: I am not affiliated with GOG or Valve in any way, except that I give them some of my money sometimes, in exchange for data.