"New deals everyday and hundreds of of deals all weekend".
Way too many games to list. A few standouts are Black Ops, Mass Effect 2, Portal 2 and Orcs Must Die.
Black Ops is 50% off, $44.99 (originally $89.99)
Orcs Must Die is 75% off $3.74 ($14.99) + DLC
All prices are in USD.
EDIT: I just sunk $95 into this sale. I didn't buy much of the big titles, but I took this chance to buy a lot of the indie stuff that have been heavily discounted at 75% off. I try to support the Indie Developers as much as I can.
Some purchase highlights are Mass Effect 1 + 2, Spectromancer (Designed by Garfield, who also designed Magic: the Gathering). Orcs Must Die + DLC, Dungeon Defenders + DLC, Fortex 2, ARES (For Megaman X fans), Commandos Collection (3 awesome games for less than 4 bucks?), NightSky (designers of Limbo), and a whole lot more. Awesome sale so far. I almost fear for my bank account for the other upcoming sales the next few days.
Which games did you guys purchase?
List of all specials: http://store.steampowered.com/search/?specials=1