Go to CycleBar for a great workout that will make your legs feel like jelly!!! This is an awesome spin experience- the bikes are in super condition, the music is great, and I love how they turn the lights down so you don't even think about everyone else seeing you sweat like crazy. They also do one track in each class with a weighted bar, so you get a little upper body workout in there, too.
You can reserve a bike online or at the front desk, so you can stake out a spot of your own wherever you'd like. They provide shoes (not gross bowling shoes, these are nice and CLEAN), lockers, water bottles and filtered water, and spotless locker rooms. The only reason I am giving it 4 stars instead of 5 is because I have been kind of weirded out by some of the language used by the teachers- I'm sure it hypes most riders up, but I don't love it.
But you know you will get a killer workout and have a great time at CycleBar!