Hotel Prince - Paris, France 

I've been to Europe 4 times for a total of about 3 months, and this is by far the worst hotel I've ever stayed at. While there, my MP3 player was stolen from my room, and each individual I told about it was less helpful than the next. Finally I spoke to the manager who said he was sorry, that he would question his maids, and to call back in a couple days. I called 7 times over 2 weeks, while each time the receptionist said the manager was not there, or wouldn't be back for a few days. The security is horrible, there are several different receptionists who hold your key during the day, and there is no one at the desk at night. Aside from that, the rooms are tiny and run down, and the bathroom is so small your knees hit the tub when you're on the toilet. But the unbelievably bad service from the personnel makes this hotel a must avoid.