This weekend Brink is free to play until Sunday at 1PM PST. Brink is also on sale for 50% off, bringing the price down to $24.99.
The Doom & Quake complete pack is just $29.99
The Quakecon pack 2011 (34 games including Brink and Fallout New Vegas) is $69.99
If you pre-purchase Rage, you can also get a bonus item for TF2 and an additional 30% off the Quakecon Pack.
If you pre-purchase Skyrim, you get a TF2 bonus item and an additional 20% off the Quakecon Pack.
Check in each day until August 7th for more deals.