Who here is as addicted to getting Achievements as I am? Same goes for Trophies. What's the toughest one/ones you've ever gotten?

Neighborhood Watch on The Orange Box was the cheapest thing I've ever had to do in a game. Save all the buildings outside the silo from destruction. Probably wouldn't be that hard if I attempted it again but at the time it was really tough.

A couple of the skulls in Halo 3 were real bitches to get too.

Your turn. Gogogo!