If you haven't fired up Steam in a while make sure you check out the specials on right now, I think they're planning to do several specials in 1-day lots. It's all so very tempting. I'm keeping fingers crossed for a L4D2 deal this weekend.
Check out some of the deals here
Some deals in the current batch: Far Cry 2 US$9.99, GRID for US$7.49, Batman Arkham Asylum US$24.99, plus a lot more. The Lucasfilm pack is tempting me at the moment, just for nostalgia's sake...