Well, the first thing is your major, are you a serious student, the distance to your classes, where is the chow hall. How cold/hot is the room. For example, lets say you are an engineering student, there should be a dorm near the engineering class rooms, for serious students. Another dorm might be for freshman, before they flunk out. Likewise, easy access to food is important. Single rooms are nice, and for the serious student. After you get there and settled in, make a search for the best room in all the dorms for your situation. Then get it and keep it until you graduate and move on. You will figure out all the factors for your situation and find what you want by looking around. You already have made a good start.