To the OP. Try playing Magic Cards. Unlike the belief from morons who haven't given the game more than a ten-second look, it's a very deep game that requires a lot of strategy, and it's just fun as hell as a pickup game.
It's similar to chess in the notion that the goal is to defeat your opponent (but unfortunately, due to card draws, there is a pretty small chance element)
You build a deck (there are tons of types... you can do a cheap creature deck, a deck that forces your opponent to remove all their cards from the game... a deck that uses flying dudes, steal the other players cards until end of game, etc. etc.), and you play against other people.
It's not a fanatic game where you have to dress as a wizard to play, and you don't have to play like these games are portrayed in shows/movies. It's got a huge demographic that play, people are genuine, and they are all logical thinkers, because that is the root of the game.
Anyways, if you haven't tried yet, get this on XBL (if you have an Xbox... I'm assuming you do if you play Halo). It is one of the most addicting things I've gotten into, and it's not a brain-rot activity like sitting and watching reality TV (which a lot of people tend to do these days). It's stimulating, makes you plan moves ahead, has a creative element, but isn't as 'intense' as an 'intense' chess game would be haha.