I have two degrees from the UK, and am currently doing a PhD in the US. During the application process I visited 8-10 different graduate schools in the states, and honestly, I felt like any one of them would be comfortably in the top 5 in the UK.

Maybe that's a totally superficial assessment, but in terms of the quality of facilities, research going on and the interaction I had with professors they were awesome. I don't think this is surprising though - the US is a lot bigger (and I visited a lot of the top universities) so you'd expect there to be more high quality institutions, because there are simply a lot more students/faculty.

This is why I find the UK occupying a lot of the top ten to be someone dubious. No slight against the British academic world, but four out of the top six when adjusted for funds and population just seems ridiculous.

It may have something to do with the fact that ranking organization is in the UK. The same thing happens with a few other 'academic' rankings I have seen.

As long as prestige factors heavily, Cambridge and Oxford are almost always going to be in the top 10; they're both almost 1000 years old.