I was deciding between mad men and sopranos, watched one episode of mad men and was bored out of my mind.. now i'm in the middle of season 2 of the sopranos
I like Mad Men - I don't love it - I like it.
Sopranos head and shoulders - with multiple payoffs during the run. The ending is polarizing, of course, but regardless of what you think about the ending (and some people have an issue with the Dr. Melfi scenes, as well) - the show itself is a wonderful drama - one of the best of all time.
Mad Men - for a historian or a person with a particular interest in the history of advertising - is a fine show, don't get me wrong - but it starts really, slowly and kind of plods along for a while. Not a GOAT candidate, by any stretch, but quality television, nonetheless.