Or Scrabble :) I've recently got rather addicted on Scrabble and it's amazing how much you soak up if you actually look up the words that get played against you (and if you play against a computer, it'll play some crazy stuff against you). iPhone Scrabble is now my main addiction..

Big +1 for bridge. So simple, yet so sophisticated, it never gets old. I play in a duplicate tournament once a week, on-line when I get a chance, but probably most of all, I have a bridge game on my palm pilot that I carry almost everywhere. I squeeze in a few hands several times throughout the day, often imagining my cousin and I kicking Warren Buffett's and Bill Gates's asses.