A Motel 6. It smelled so bad when I walked in to the room, I turned right around went back the the front desk, handed him my key and left the property. Never asked for a refund, change of room, nada. I was done with that chain and have never been back.

I had a weak hostel room in Aquas Calientes once where the rain leaked through the roof all night, but I knew I wasn't getting much and it served the purpose of keeping us mostly dry