Steam yesterday: Age of Empire II HD $4.99 (75% off). DLC also $4.99 (75% off).
Steam today: Grim Dawn, the early-access Titan Quest clone from the Titan Quest guys. QT3 thread $20.09 (33% off).
The weeklong link is above. I noted the following (not necessarily good):
Race The Sun QT3 thread. QT3 article(s) $4.99 (50% off).
Dysfunctional Systems: Learning to Manage Chaos $0.99 (80% off).
Super Sanctum TD $0.39 (90% off). Has trading cards, which might pay for the game itself…
Teleglitch: Die More Edition $6.49 (50% off).
And some series like Crysis, Dead Space, Painkiller, Earthworm Jim, Starpoint Gemini.