I'm a fan of the UNLV gym. I can always find a free day locker in the women's locker room, there are always machines available, and they offer a lot of options to maximize your workout (classes, cardio machines, weight lifting equipment, indoor track, swimming pool, etc. etc.). I played racquetball here for the first time the other day and I am definitely a fan now!
As a student, I love the accessibility. I can park anywhere on campus and walk to the gym (I consider it part of my workout) and I can do my own thing without being bothered or work out with some friends. I love that it's included in my tuition and offers all the same stuff as gyms other people pay for. Also, the hours during the semester (6a-12a M-F) are great and offer no excuses to fitting in a workout.
If you're a UNLV student, definitely take advantage of this opportunity and use the gym!