I've never been an avid gym go-er, but dammit I've tried! Of all the gyms I've attempted to make a habit of, this is the one that could have made me a gym junkie. If only I wasn't so good at TV/movie watching. Oh well, we all have our talents!
Planet Fitness is the only place I've seen an Arc machine. It's a cross between a stair stepper and an elliptical that gives a serious burn. Twice the calorie melting as a regular elliptical and easy on the joints if you have bad knees.
I was also a huge fan of the price. Basic package is $10 a month with no contract, which is awesome for gym quitters like me. This gym is clean and has very nice locker rooms. I'm also a big fan of the circuit training for when you want to get in and get out without getting in the way or waiting a long time for machines. Give it a try, you won't regret it!