The Steam Holiday Sale is on now through Sunday, January 2, 2011. Gamers may save up to 80% on select titles, with daily and week-long savings on featured titles, publisher game packs, and compilations. In addition to the usual savings specials, each day of the sale will feature a special Holiday Bonus on one select title. The twist: Players must qualify for the Holiday Bonus by owning another Steam game. For example, the first Holiday Bonus is Portal - save an extra 10% if you own Half-Life 2. If you already own the title, Steam will automatically detect this and offer you the 10% savings during check out.

Meanwhile, titles kicking off the traditional savings include:
F1 2010 50%
Battlefield Bad Company 2 66%
Fallout 3 (Game of the Year) 33%
The Deus Ex Collection 85%
LEGO Batman 75%
Peggle & Peggle Nights 60%
Prince of Persia (Franchise) 75%
Portal 75%
F.E.A.R. (Franchise) 75%
Titan Quest Gold 75%
Super Meat Boy 75%
Oddworld's Oddboxx 50%