I went uni in Oxford and it's not all that. The city center is tiny, shopping is awful and the nightlife is pretty lame. The Oxford Uni buildings are genuinely amazing but that is all Oxford has. The cotswold villages and neighboring market towns are genuinely nice places though.
I'd honestly rather go university in Nottingham or Manchester. Awesome cities imo, haven't seen much of Sheffield but had 10 minutes to browse whilst waiting for the train to Leeds and I was very pleasantly surprised with what I saw.