The highlights of the sale are certainly the Deus Ex's Missing Link DLC and co-op adventure Lara Croft and the Guardian of Light for 600 MSP ($7.50). There's also some attempted discounts on full downloads of Battlestations: Pacific, Just Cause 2 and Tomb Raider: Underworld; but chances are you can find better in your local bargain bin.
Another game worth checking out is updated original Tomb Raider: Legend: Anniversary, available in two chunks at 400 MSP ($5) apiece (caveat is you'll need to own TR: Legend since it's the DLC). So, try the first two levels before you buy the whole thing. Find the full list of discounts after the break.