Valagetti said:
Whenever I finish a section from L4D2, the generic rock is so... generic, but its to do with Skinners box theory. Most of these posts I'll predict will be about something to do with any random sound made and that will be part of the reward process.
When you finish a campaign section on highest difficulty, that becomes the single most relaxing and rewarding sound in the world.
OT: Mine would probably have to be the sound of the Squad Cannon from Killzone 1. I bloody loved that game, dispite it's flaws, namely because it had both kickass combat and even more kickass weapons, and the Squad Cannon was the most kickass of them all for me.