Brett and Burke, much more believable as Holmes and Watson than Basil Rathbone and Nigel Bruce, although I would rate them as equally entertaining each in their own way. Rathbone's Holmes was far less believable with his many easily penetrated disguises while the bumbling Watson couldn't have been trusted to doctor a dead horse. But a lot of fun nonetheless. And, of course, Jeremy Brett and Burke are making a TV series, not a war-time set of movies which sets them apart but, in addition to making Holmes more believable and far more cerebral, they are a much more interesting team who make Holmes much more as he was in The Strand, a true mystery, not a joke.
Also, a top hat is much more believable for a Victorian gentleman than a Deer Stalker.