In my last job I used to stay in the same hotel in London for 2 or 3 nights nearly every week for 3 years. I kept a list of my room numbers and what I liked/disliked about each. So after a few weeks I knew which rooms I wanted and asked for them at check-in. It's an interesting idea for an web site but it would be hard to gather sufficient factual (as opposed to qualitative) data to make it useful. TripAdvisor is a good resource but comments tend to be qualitative rather than factual. What makes a "nice" room for someone may be different to my criteria. Likes and dislikes are so personal.