I asked my dean today and although he's no expert on uk uni entrance, he had some kind of idea. Basically in past years, when guys from our school applied to uk unis, they couldn't really care much for IGCSE's, especially since most of us have 5 a-levels. The only exception seems to be medicine. So regarding your question of which specific unis accept 5 IGs, well it depends entirely on your situation (what marks you got, what degree you want to do, a-levels ....... etc).
But he did tell me that since people have gone to Oxbridge with only 5 IGCSE's, it seems highly unlikely any university would turn down an applicant solely because of IG's (except of course the already mentioned medicine category).
Nonetheless if you do insist, I managed to get a list of my school's uk entrances (everyone had only 5 IGCSE's) in 2008.
Cambridge (I mean the UK one if anyone is still unsure).
Oxford
Manchester
Imperial
If your interested, all universities in NZ accept 5 IGCSE's. In fact all you really need is a C in AS English to get into NZ unis, and maybe half a brain
And finally, if that isn't enough, here are the following US unis/colleges that have accepted 5 IG people from our school, again it is the 2008 list:
Columbia University
Cornell
Florida
Stanford ? (Not sure on this one, dean insisted one guy applied and got in but I never heard of him so meh..)
Hopefully that list is enough although I do remind you that everyone in our school does 5 alevels so maybe that's why unis have been a bit lax on IGCSE's to us.