minesweeper
i love this game. in college, freshman year in the dorms, i played dozens of hours of minesweeper. literally dozens. and i got to the point where i could reason out two or three or four squares quickly, basically in real time, and be able to just cruise over the board, marking bombs and clearing other tiles steadily. but the really fun ones are the ones where it looks almost like you reach out by magic and know that that one right there was one, or wasn't one. tyler would occasionally play (jezzball was his game), and every once in a while he'd call me over when he got stuck. 'dave. come look at this. is there anything i can do?' because it's lame to just guess. the beauty of the game is when you don't have to guess. you can know with certainty that this or that tile either does or does not have a bomb. so i'd get up and go over and lean down and stare at the screen for a minute or three, and then i'd either say something like 'okay, this one right here has to be a bomb, because the number one over here means there can't be both of this two's bombs in these two spots here, which means that one of them has to be right here.' which sort of thing he would either follow or not quite follow, as the case may be. or i'd say 'no, you're fucked.' and he would have to guess.