Well?
Basil Rathbone (the original films)
Jeremy Brett (1980s TV series)
Robert Downey Jr. (New films)
Buckyball Cabbagepatch aka Benedict Cumberbatch (Sherlock)
Jonny Lee Miller (Elementary)
Barrie Ingham as Basil of Baker Street (The Great Mouse Detective)
Hugh Laurie as Dr. House (House) (well look at you being all meta!)
No one is as good as Sir Doyle's original character
Other
Well?