Rathbone was the one I grew up with, and though the stories were frequently poor, he was magnificent as Holmes; intense, irascible, but quite brilliant and underneath it all, at some level, compassionate. Nigel Bruce was TOO much of a bumbler compared to the books, but he worked as a foil for Rathbone for the length of a movie.
They made me want to read the books.
Then when I was older and I HAS read the books, we had the sublime Jeremy Brett as Holmes, and he simply WAS Holmes... with all the fascinating flaws that even Rathbone wasn't allowed to get away with. And Edward Hardwicke as a suitably implacable Watson, nobody's fool, and intelligent by any ordianry measure, but completely outclassed by Holmes in terms of reasoning.
It was a great era for detective TV fiction - Brett as Holmes, Joan Hickson as Miss Marple (We will not speak of the more recent Geraldine McEwan Miss Marple out of respect for Ms McEwen's other sterling work) and David Suchet as Poirot (Thankfully we still have Suchet, and more of his Poirot to come!)