Mad Men is the first drama I've come across that I can unbiased say gets better every season. Season 1 is a lot of fluff and gets boring in spots because it focuses on Don/Betty and introducing the characters and nothing really happens until Draper's brother seeks him out, then things pick up a little as it gets into the Kennedy vs. Nixon election, but still they don't go into much of the creative process until later on and choose to focus on the attitudes of the characters and how they interact.
By the beginning of Season 2 though things get interesting. Jimmy Barrett adds some comedy/intrigue early on, Peggy starts settling into doing copyright, and before you know it you start picking out your favorite characters and hang on their every word. That's what makes the show great, the whole really is greater than the sum of its parts because the parts come together so well and there are so many of them. It's hard to imagine watching people just do what I would consider a boring job some 50 years ago would seem interesting, but I put off getting into the series until the end of Season 4 and now I'm through it 2 full times already, so there's definitely something to it I can't put my finger on but it works.
Then when you get to The Suitcase episode in Season 4 it's like shooting your wad twice and feeling like you can go another 2 times after what happens between Don and Peggy. I can't imagine having to wait another week for the next episode after that. Jon Hamm submitted that episode to the Emmy voters too, and while I've never seen any of Friday Night Lights it's just hard to imagine anybody topping that.
