While I would have to take more time deciding between RD Jr and Basil Rathbone (I think Basil wins), Robert Downey Jr's Sherlock is I think the most relevant for today. Both Basil and RD Jr bring the character to the limits of acceptability for their time. Guy Richie is surely to be credited for that and Basil most likely did it on his own, but few actors could carry this mix of such a complex persona without alientating the entire audience and for Sherlock Holmes in particular, I think Robert Downey Jr. is the only one who can do this. He even made me like Jude Law! It was close with Benedict's, he is an awesome actor and I love his Sherlock despite the different type of humor they throw in but the others don't even compare in my book. Though to be fair to the actors, it's the entire depiction of Sherlock Holmes I do not like. Between Benedict, RDJr and Basil, they all preserve the story of Holmes as created by Sir Arthur. The others are either standard TV Tripe or as in Ian's case, an entirely seperate outlook.