At least they aren't sitting around BSing with each other while ignoring you. I guess either way, it stinks.

I would go to the gym staff and tell them your issue. Let them deal with it. I know what you are talking about with the enormous weights, that's just not going to happen. My gym has two machines, maybe it needs to be pointed out that on their next equipment purchase they should invest in another?

That or go a half hour earlier than usual and take over the machine?