Our dbells stop at 120lbs and then there is a set of 155lbs and 165lbs on the floor. Apparently you can't get insurance for dumbbells over 120lbs or something.
We've got 150's. I'm the only one that has ever used them. For that matter I unpacked them from the crate and put them on the rack. I'm sure there are a couple guys that could bang them around too, but they don't.
We have a couple of 200lbs laying around. They look nice sitting in the corner, I have yet to see anyone doing anything cool with them other cheated db rows.