When I was lifting, it was from 30-60 minutes depending on body part. Legs took longer because I love leg workouts. At one time however, I could spend 90 full minutes doing strictly a leg workout, no cardio at all.
Can depend on how crowded the gym is, but typically 35-45 min, 3x a week. But, like JJ, might last 60 min if I get interrupted or if there are a lot of people there.
I used to lift for like 90 minutes, 3-5 times a week...now don't know what the hell I did to lift that much and that long! Oh, and I am seeing MUCH better results NOW.
We're there usually for an hour and a half to two hours...but that includes waiting on each other for spotting and such... it is also in the morning when we aren't capable of moving terribly fast...
when i was in the gym i never timed myself... never really paid attention to the time (until i got home and i was already an hour late )... i think if you measure your workout in minutes (unless it's cardio and then its milliseconds for me ), you're really doing yourself an injustice, if you aim to be out in x minutes there's a good chance you could be over or undertraining...
try to choose a time when you don't have to set a schedule and listen to your body...
that said, my workouts were usually 45min give or take, but some days i'd go in and look at the weights and say not today, somedays i'd be in there an hour and a half...