These days I always play for 3-4h max (and only if I really love the game)....but I remember one time back when San Andreas came out for the PC, my parents both had night shifts so I was alone. I started playing around 9pm and was planing to play maybe for an hour or two. Little did I know that I was at the "flying school" part of the game. Fast forward hundreds of tries to beat that part I suddenly started hearing birds, that's when I realized that it's 6 am in the morning and that my parents are just about to come home...In short, I played San Andreas for 9h straight.