Go down into the dungeon. Kill everything you meet. Backstab your friends and steal their stuff. Grab the treasure and run.
Admit it. You love it.
Munchkin is the dungeon experience . . . with none of that stupid roleplaying stuff.
I myself was introduced to this hilarious card game by a college friend of mine. He showed me the original, which is basically a parody of dungeons and dragons and the like, and this past Christmas I was given The Good, the Bad, and the Munchkin, which is a Wild-West themed version. It's a lot of fun and most people I've played it with get the hang of it after their first round.