darthdevidem01, Oxford and Cambridge are equal in all respects. Pay no attention to the league table, they are run almost identically. The reasons to pick one over the other are limited to how the course works and whether you like the 'atmosphere'. I preferred NatSci to straight Physics, hence Cambridge.
London is extremely expensive; I wanted to apply to Imperial but couldn't afford it without getting a job while at uni which is not really an option if I want to do my best. London universities don't really do accomodation for more than the first year; Cambridge and Oxford are the only ones I know that (sometimes) offer accommodation for all four years.