been w/ Bally's since 99. My monthly bill is around $9. It lowers each year you are with the gym. Depending on location Bally's can very in quality. The one I go to is very nice though. Tons of machines, smith machines, cables, free weights from 5lbs-100lbs, a lot of tread mills and ellipticals, steppers, running track, pool, sauna, hot tub, aerobic room/classes, juice/protein bar, etc.
One of the best perks though is most memberships will allow you to go to any Bally's in the country. Not sure if other gyms let you do this. That is a huge benefit in itself. I have been to many Bally's in several different states when out of town for vacation or business.