University of Birmingham, University of Bristol, University of Cambridge, Durham University, University of Edinburgh, Imperial College, London School of Economics, University of Nottingham, University of Oxford, University of St Andrews, University College London, University of Warwick, University of York
To the best of my knowledge, this list has not been updated. Thus, I looked at the three current rankings (i.e. the 2012 ones) of the Times, Guardian and Independent (also here) and quickly calculated the combined rank: Now, the top 13 are (in alphabetical order with the actual rank in brackets):
University of Bath (10), University of Cambridge (1), Durham University (7), University of Edinburgh (13), Imperial College (5), University of Lancaster (9), London School of Economics (3), University of Exeter (10), University of Oxford (2), University of St Andrews (4), University College London (5), University of Warwick (8), University of York (12)
What has changed? Birmingham, Bristol and Nottingham are out, and Bath, Exeter and Lancaster are in. Interestingly, the first three are part of the Russell Group (the biggish research active universities), whereas the latter three are part of the 1994 Group (the smaller research active universities).
Finally, as always, needless to say that doing such kind of combined ranking is a nice thing to do on a rainy Friday afternoon but it has its obvious shortcomings.