There is no agreement at UCSD on which are the best or worst dorms—most people say they like the dorm they are in the best. But, if pressed, Revelle seems to have the slight majority for being called the worst dorm, probably because it is the oldest and the ugliest. Some people really like Camp Snoopy (Sixth College dorm), and other people hate it. Roosevelt College, which is the newest residential hall, is the most comfortable and has become a favorite. Do not trust the dorm rooms you see on TV shows. All the rooms at UCSD are going to look very small when you move in. It is a good idea to try and see a room in the dorm you will be in before you move in, so you can better decide what to leave at home.
Dorm assignments are completely arbitrary and only based on what college you are in. Most students find that the people they meet and live with influence their dorm experience more than which dorm they live in. Overall, as long as you are flexible and try to get along with your roommate, the dorm you live in is not that important.