IMO it was THE greatest. It was the first TV show which I recall bringing Cinematic, movie quality, in terms of acting, scripting, budget and drama to the small screen. His performance was as good as any other of the great gangster actors - Pacino, Deniro, Cagney - more so in fact, in that in the show, we saw so many sides of a complex character played out brilliantly.
As a tribute, last night I got out my Sopranos box set and watched the first episode of season1 again. It was fantastic and I had forgotten all about the ducks that started it all.