I agree with Wrholt, although it sounds very weird for us "me gustaría un cuarto/una habitación".
When we're at a hotel, we don't really feel we have an option to spend the night, so we actually need the room.
It's not exactly the same when you're at the restaurant and you can choose what food would please you the most; then "me gustaría una ensalada" is more natural to say.
Yet, if you're so very thirsty, you may buy a bottle of water saying: "necesito una botella de agua".
