I train for 2-3 hours most times I go to the gym, but I only train 3 days a week.
I should note that the aim of the game isn't to be in the gym as long as possible. I'm a proponent of minimalistic training - do what needs to be done, then get out. It just so happens that with Olympic weightlifting being my priority, it takes about 1.5-2 hours just to get in some good practice on the Oly lifts, and then I set aside an extra hour or so for less technical, more brute strength exercises, prehab and possibly some conditioning.