Quite a few in my school including Ben Kingsley, Robert Powell, Mike Atherton and John Crawley. Three who were there the same time as me (and I knew) were Sir Nicholas Hytner, Director of the National Theatre, Sir Howard Davies, ex deputy governor of the Bank of England and Martin Sixsmith, who was the BBC correspondent in Moscow & Washington and was the consultant on The Thick of It.
I then went to what was then Manchester Poly, one person who was a contemporary of mine was a man called Paul Walsh. We must have shared a few classes but I didn't know him. He is now CEO of Diageo, the company that owns the Guinness & Smirnoff brands among others.