I don't know what you're trying to differentiate. It's consistently the same dozen or so universities that attract wealthy or well-connected people. It could be a range of factors from better education and upbringing to simply having the right guidance or wanting to be with like-minded people. One factor many of them have in common are strengths in the arts and humanities. Many of them also tend to be institutions that value tradition.
From my experience I would narrow it down to Oxford, Cambridge, Durham, Bristol, St Andrews and the old London colleges (University/King's), possibly Edinburgh.