Just purchased killing floor (yesterday) for 4 quid! Think I'll be getting value for money from that bad boy. :)
There were some ridiculous bargains to be had - I didn't buy any this year as upgrading my PC first, and money is tight. Got a few to play through first too.
Highlights I saw were:
GTA IV Complete for £6.50
B:BC2 for £6.50
Oddworld: Stranger's Wrath for £7
Just Cause 2 for £5
HAWX 2 for £15
plus numerous others...