I'm interested to see how much people bought over the Steam sale, I'll go first.

Tropico 3 Gold - £4.99
Lara Croft Guardian Of Light - £2.49
Sanctum - £2.49
Splinter Cell Conviction - £4.41
X3 Terran Conflict - £4.99
Borderlands Claptrap DLC - £1.57
New Vegas Dead Money DLC - £2.24
New Vegas Honest Hearts DLC - £2.24
Nation Red - £2.71
Gratuitous Space Battles Complete - £7.49
Tiny Big Bang Story - £2.38

Total: £37.5

Amazing how one small impulse buy a day can add up :S. Sometimes I wonder if I like collecting games more than I like playing them!