Ancient Domain Of Mystery is really good, pretty complicated and the hotkeys are a pain to learn though. Tales of Maj'eyal is fantastic, makes you learn to be cautious and plan your actions or you'll die a lot. I suggest adventure when starting the game to learn it and switching to roguelike later. Jet Set Radio absolutely fantastic. There are emulators to, if you want to introduce him to the mario franchise or something, just make sure to have a controller because playing with a keyboard really blows for them.
From the big bang theory: "how about a ten year old girlfriend?" Maybe weichi/go/igo or chess, something that's really simple and also not simple Besides there are really cute girls in these board games to find, attend a tournament