Does anyone have a specific game they go to after putting a long time into a game?  A game that, for you, in a palette cleanser of sorts?  Maybe you have a few or maybe it's just one.  I'm not asking if you have a game that you consistently play over and over.  I'm asking if you have a game that you go to between new games. 
 
For me, I'd say Metroid: Zero Mission and Street Fighter IV are the ones I go to consistently.