I've been a member of 4 gyms, Bally's being one of them. I'm not a fan of Bally's, they kept moving the machines around, my trainer quit and nobody bothered to call me, they kept taking money off my credit card even after my membership expired, etc. You should take tours of the gyms in your area and decide from there. Look at who is working out (is it all muscle men?), what kind of shape the machines are in, how much are their trainers per hour?, what the class schedules are like (for aerobics, yoga, spinning), are the staff nice or stuck up?
If you're new to working out you should see a trainer at least every 6 weeks.
I should have paid more attention when I went on my tour, I would never have joined.