Gielgud vs Olivier
@Everyone who reads the posts about "Brideshead Revisited":
The section "Trivia" about "Brideshead" on the IMDB prints the following remark:
"Laurence Olivier was offered his choice of roles in either Lord Marchmain or Edward Ryder (which ultimately went to John Gielgud). Olivier picked Lord Marchmain, but later regretted the choice as he realized that Edward Ryder was actually a much stronger role."
I cannot IMAGINE that Olivier, despite his great abilities as an actor, could possibly have played the part of Edward Ryder as brilliantly as Gielgud.