Probably Animal Crossing since I played that for about a year plus then CoD:WaW. After a few months I am betting Monster Hunter Tri will overtake CoD:WaW. Smash Bros would be top game for me or close to it except I don't have any real life friends to play it with / want to play it since they aren't too good at it. I don't really like online mode too much (it doesn't lag too much but the lag doesn't feel right at all while playing Smash).