I am British and completed by undergrad (English and French) at Oxford. What most people don't know is that it's a public university and costs no more to attend than any other university in the UK. You'll be shocked at how little this is: currently £3000/ year, and just one year ago it was £1,200!
I LOVED it there - I think it's the most intellectually-stimulating, gorgeous-looking, friendly, interesting, opportunity-filled place I could have gone to. But I think that anyone wanting to go there to enhance law school prospects alone shouldn't. I happen to think that undergrad is a once-in-a-lifetime thing - it can't really be lived with the same intensity twice. I'd definitely recommend an MPhil/MSt instead.
I miss Oxford