I stay at a lot of business hotels, when I am on business travel, and a couple of times in really luxury hotels when I am travel on private reasons.
Well:
Business hotels like Sheraton, Westin or Hilton I expect a clean, rather big, efficient room which allows also to work, and a good bathroom, service, well I don't expect too much, everything anyhow is run based on time efficiency.
Luxury hotel:
I have stayed at a couple of them like some Ritz Carltons or Four Seasons, but I am coming of my most wonderful experience ever last November. I went for a weekend to Paris with my wife, I always had a dream of staying of one of these super hotels in Paris. After long searching, we finally decided to go to the Plaza Athenee in Rue de la Montaigne, the hotel where also now Alain Ducasse has his restaurant. I can only say wow, I always thought that e.g. Ritz Carlton is already top notch, but against the Plaza Athenee it is only garbage:
1) First the hotel doesn't accept any tourist groups nor does it accept any politicians ( no kidding ), they are much too worried with their normal clients.
2) You step in the hotel and your royal treatment starts, no hassle, no rushing just elegance, check in is so calm and then suprise, surprise they upgraded us to one of the Junior Suites with a view on the famed garden of the Plaza.
3) the hotel bar which is a very hot spot ( I have never seen so many models) is only open at night for hotel guests
4) Service: You never see it or feel it, but it is always there when you need it.
The list goes on and on, that is what I call a true luxury hotel.