What would you do if you ended up with a horrible hotel/motel stay?

If you booked a hotel/motel and the stay was absolutely rotten what would you have done about it? What if you found the towels dirty or simply not there? That the place noisy, fridged cold or steamy hot? If you brought up any of the things that were not proper to the service staff or the front desk did they correct the problem or act hostile or apathetic? For this horrible experience how much did you pay a night for the privilege if poor service? Would you slam them on any Web site you could leave a review?