This is obviously the mecca of the Phoenician mountain hikes, and deservedly so. Camelback is the perfect mix of central location, unparalleled views and, most importantly, a grueling workout. I love hiking this mountain because of the mix of rock types. It starts out as red rock near the base up to the hella scary rails, then very suddenly changes to a granite look-alike (Anyone know if that's actually granite about halfway up? It sure looks like it.) The last leg is bascially boulders that you have to crawl over, but the view at the top is an unbeatable 360-degree view of the Valley. Though South Mountain has a more centralized view, on Camelback you really feel on top of the whole Valley.
My only complaints: First, the parking is a nightmare, especially on the weekends. Perhaps it's just due to its reputation (and the surplus of multimillion-dollar homes in the area), but it can be hard to find a spot. Plus, people like to jockey for position on those rails, especially coming down, so be careful you don't take a tumble.