Steam sends word their Autumn (US) sale is now on, where they'll be offering daily discounts on numerous titles, kicking off today with huge discounts on some very well-known games, including Call of Duty: Black Ops (50% off), Portal 2 (66% off) and Mass Effect 2 (75% off) among many more.
They also plan on having "hundreds of deals all weekend", so you'll need to keep an eye on the Steam Store to know what's in the bargain bin.
For more info just head to www.steampowered.com
. And be sure to drop a line in the Comments if you find any hidden gems.