i lived in rootes in my first year. it was great. it's laid out in a corridor-, as opposed to a flat-style, so it's pretty difficult not to get to know everyone around you and be sociable. it's right behind the union (although not as stupidly near as whitefields, which i always think must be a nightmare, as you hear every thud-thud-thud of the union, every single night), set overlooking a field and lake (summer picnics and evening spliffs) and i would say its charm lies in its dinginess. no en-suite here, it's the proper student experience; and as everyone's in the same boat, it leads to great cameraderie and atmosphere. i really did. not. want. to leave! i recommend rootes to anyone.
i have not heard great things about lakeside, jack martin and arthur vick, though. these are the high-end, en-suite halls. friends reported a populus of pampered, private school oiks, assorted, asocial oddbods and gangs of international students who obviously can speak english but don't seem to want to outside seminars.
i would recommend going cheap 'n' cheerful.