People who are funny, intelligent, kind, fun, empathetic, passionate, honest, adventurous and appreciate the world beyond them, or can at least acknowledge it exists. People who aren't selfish and petty.
I admire people who aren't satisfied with easy answers; you don't have to be happy all of the time. Have opinions? Good - as long as you can handle other points of view. People who think critically, embrace emotions instead of running away from them, possess ambitions, and don't feel the need to bullshit constantly are unique. Of course, being polite doesn't hurt.
If you care deeply about someone or something beyond yourself, I want to know you. Also cool: people interested in more than drinking until they pass out, smoking bowls, and hooking up with someone they don't know. If the driving purpose of your life is to impress your friends by how much you can buy, imbibe, or get away with, then we probably wouldn't want to know each other. You don't have to be a professional do-gooder. Just don't expect applause for being an asshole.
Bonus: People who appreciate the humor of Will Ferrell, Michael Ian Black, Hal Sparks, and Steve Carell get big high fives.