P G Wodehouse was shown recordings of Ian Carmichael as Bertie by Frank Muir, head of comedy at the BBC in the sixties, and was very impressed.
Although it was generally agreed that Carmichael was a little old for the role, I don't think anyone at the time could have matched his style and flair (except, perhaps, Richard Briers?)
Wodehouse considered Dennis Price 'the definitive Jeeves', but all this was, of course, many years before Fry & Laurie came on the scene.