They also might notice that I usually wear t-shirts with math on them.
Bridge, Poker, Dominion, Catan, Saboteur , Scrabble, Coda, Tichu, Stoicheion(a game I am currently developing), DnD 3.5, Andantino, Braid, DROD, Pikmin.
4. Intellectual Discussion
Philosophy. Specifically thinking theoretically about how I make decisions and determine what I believe.
Games. If a game does not inspire be to spend time outside of the game thinking about strategy, it is not good enough.