The Arena District Athletic Club is one the most friendliest and cleanest gyms out there. The staff is incredibly helpful and friendly, they really try to learn your name, which is something small but nice. The equipment is brand new and always clean. The cardio machines offer TV's at each location for your enjoyment while working out.
This is not a place where people go to be seen. It's not a single club, its a place to work out. People are serious about staying fit and the nice thing is there aren't "muscleheads" running around everywhere.
They also offer a variety of classes that are included with your membership from Yoga and Pilates to spinning and boot camp.