If you have access to it, play the original Animal Crossing. I don't know why, but that is the only game that has ever put me to sleep. I used to have a wrestling theme in my basement, and would often have my character lie down for a nap before I dozed off.
I was playing late at night one time and apprently fell asleep right in front of my Gyroid.. The 2AM music woke me up, as did the walking noise of several of my neighbors footsteps on the ground.