Again, I prefer the Dowd YMCA because it's huge and has pretty much anything you'd EVER want from a gym. I head to the Gateway Y when I need a quick treadmill work-out or lift and nothing else. The Uptown Y provides a nice middle-ground.
Located right off Tryon at the heart of downtown, the Uptown Y is super convenient: you can walk there during a lunch break or immediately after work. It's not as big as the Dowd, but it has great equipment and classes, and it's pretty modern after recent renovations.
There's a half-court basketball set-up, which allows for pick-up games and shooting. i prefer the full-court action at the Y, but this isn't a bad alternative. The best thing at Uptown branch, though, is its huge pool--great for laps and other water workouts. Check it out: it's impressive.
Overall, this gym has a really new, clean feel, which is obviously something you'd want from a gym. Never too crowded, either.