LA Fitness (http://www.latifness.com)
Lifetime Fitness (http://www.lifetimefitness.com)
Uptown Energy Fitness (http://www.efitnessgym.com)
LA Fitness is extremely well maintained but finds every excuse in the world to close, and has shortened weekend hours. I love the equipment, which is bolted down, but, I don't like the hours as much as some other places. It's a great gym, all things being said.
Lifetime Fitness is top-of-the-line everything: customer service, equipment, facilities; open 24 x 7, 365 days a year. My only gripe with Lifetime is that their equipment is not bolted down, and that they do no have a hip sled, nor a donkey calf raise. Everything else at Lifetime is a notch above everyone else. It's truly a country club atmosphere. They don't miss any details, and their staff is beyond exemplary. E.g., the weight room (which is monstrous, is always very cool, and very well ventilated with tons of air conditioning.).
Energy Fitness is majority-owned by one of my trainers, Sagi Kalev, and the home of many champions, and has a large gay clientele. I've trained with Sagi many times, and love strutting my stuff with "Sig" but often don't get down to Dallas Proper. To train with the most popular fitness model of all time, is always fun, especially when he's your personal friend. The equipment is great, the hours are good, and there is ALWAYS an audience. It IS in The Gayborhood. My only gripe is that there are some pretty weird folks, in such an eclectic part of town. :-) One guy, a nice one, wears green neon shorts, pink neon 1/2 shirt, and is loaded (he's a high end hair dresser), and absolutely is a major fan, but, oh, my...such a queen fairy. LOL. Such is life.