Well I am talking only about artistic merit. Mad Men is not the most entertaining show, nor the most fun to watch show, etc. But I do find it to be the show of highest artistic achievement. It evokes the most tender pathos, touching one to the very soul; its subtext is masterful; it rivals Dostoevsky in its human wholeness. It holds up a mirror to the human viewing. It transcends its own characters like Shakespeare. Hamlet is no mere character in a play, he is all of us, as is Don, as is Joan. Read Harold Bloom's "Shakespeare: Invention of the Human", and his ardent defense of the bard's superiority in the canon may be transpiled to my thoughts about Mad Men's position in the TV canon without overmuch error.
That's how I feel anyway.
In my critical system 'entertainment' is not so much a consideration. Breaking Bad is fun, badass, shocking, gripping, and at times highly artistic, but it doesn't try to sustain the artistry throughout. Those former adjectives are not what I'm looking for. I want to read high literature, not genre fiction, regardless of how entertaining the book is. Most literature I love is hardly entertaining at all; who could say that they were on the edge of their seat reading Ivan's 'The Grand Inquisitor'? Yet it's one of my favorite passages in the book. That sort of feeling, of artistry, of greatness, of transcendence, is what I'm judging by in my OP.