The comfortable bed, the view from the balcony, the location.
The hairs and dried toothpaste in the bathroom, the antiquated convection heater in the bathroom, the dead flowers in the balcony planters, the waiting times at reception while staff were out smoking, on the phone or just generally absent and not responding to the bell. A staff member crashed a lot of plates in the corridor when we were in reception and the reaction to this was extremely unpleasant - around five staff members all shouting at one another and then shouting at me when I tried to squeeze past carefully to pay my bill, as instructed by the (helpful) morning receptionist. If you need to have disagreements or fights in the service industry, do it away from the customers!