Hmm, difficult question. That really depends on perspective.
In an environment where everyone has a good degree, and the subject is irrelevant, I don't think any other generalist universities have the same prestige. Except for Imperial College London and LSE as well as the UK, but these are specialist schools.
This is bearing in mind my background as an international student, job hunting in very competitive markets like Singapore and Hong Kong. These places heavily emphasize academic achievement. A degree from a highly ranked university is a minimum, you are competing not just with UK graduates but Ivy League etc.
Regardless of degree subject those universities open doors - visibly impress interviewers/colleagues, special recruitment events, etc. Degree subject matters for the rest - people would be impressed with Physics at Edinburgh, but not History. While even something like Theology from Oxbridge would be highly regarded.
People from other unis might need more relevant work experience, while graduates from these 'prestige' unis get interviews regardless. Basically people don't look past the name.
That's how 'I' measure it. Of course, people in academia and other fields beg to differ, but then again if you go down the route of 'field specific' then there's no need to discuss prestige, it's dependent on what your future career requires.
These things are probably not that relevant for British graduates though.