what game can you not resist playing when you see others playing?

for me its street fighter 4, everytime i go to gamestop someone is playing and i imediately get sucked in. ever since it was released i find my self playing it more and more. i looked recently at my time played, i am already at like 60 hours of play time.

Any good game really, and since you see them having fun you just want to play and have fun.