An adjustable bench that can go from flat to straight up for overhead presses. My gym only has one of these suckers. The rest of the benches are either flat, inclined, or straight up. And since everyone is friggin using them, its hard to get on a bench that you need. If they were all adjustable, it would make it easier.
What is the difference between the "Cage" and a power rack?
Excluding bench and power rack, I would have to either go with a lat pull/low pulley, or a reverse hyper, because that is all that is in my gym besides a rack and a bench.