Warwick, LSE, UCL, Imperial, Oxford, Cambridge, and one other one that I'm forgetting are target universities for investment banking. The majority of investment bankers come from these universities. That's not to say that you can't break in from other universities (I did), but you should be aiming for these universities if your goal is to work in investment banking.
PPE as a course, however, might or might not be the best flagship at the other universities outside Oxford listed, I don't know. Warwick's pretty good, I don't know how LSE teaches it, York is excellent for PPE (but a low semi-target/non-target) ... But if you don't care about the course quality, then just stick with the above list.