We got eight at our last game night and so decided to try Werewolf (although technically we're using the Mayfair deck Lupus in Tabula). For the uninitiated, Werewolf is a game of bluffing where a certain number of players are secretly werewolves, the rest are villagers (with various extra roles depending on group size being added) and the two groups are essentially trying to annihilate the other.
The werewolves vote in secret with everyone closing their eyes. Above you can Sterno, with his eyes open because he's dead, our friend Ben - eyes closed as he's a villager, and the fair finger of The Girl voting to devour someone.
It's really great fun and a testament to that is that you're actually supposed to have nine, not eight, players - as one player has to be the moderator. Despite this, we kept mucking up the rules enough to have a good time for several hours. It's a little wacky, but actually even less geeky than say, Munchkin, in the long run. Check out the Wikipedia article for more.