From the list, we play Risk and a lot of Settlers of Cataan, but it's a long game to be stuck playing if you get screwed on the resources.
Not on the list, however, would be;
Lunch Money (Some of the most fun you can have pimp slapping your friends)
Feudal (got my friend a copy on ebay)
Hero Quest (Could be a roleplaying game, and then again, not.)
We also playtest a fantasy boardgame my friend is creating. It's not too bad, but since the rules are constantly being changed at this point, you have to learn how to play each time you play it. Which means the games currently run three hours or more, but that should change when the rules become familiar.
Edit - Magic: The Gathering used to be up there too, but I've freed myself from it's gravitational pull. Now I waste my money on minis.