For all the emotional heft, Breaking Bad is fucking funny. That's what makes it so immensely addicting and human. My favorite shows usually strike a good balance between the two. Even a show as supposedly "esoteric" as Twin Peaks hit on a deeply human and relatable level beyond the supernatural elements.
One of the "weaknesses" of Breaking Bad is that you set your brain on cruise control during seasons 3 and 4 and begin to expect violence, and the show feeds it to you. The first couple of seasons spread out the insanity a little better, which, coupled with the unique setting and great characterizations made the show one of my favorites almost immediately. But, even with my expectations, the writers still find ways to surprise me, which is pretty impressive. I was stunned by the season 4 finale. And the characters just keep getting deeper, which helps keep you interested during the more generic portions of the show.
Also, I'm not sure if I love or hate the fact that the middle portion of every season is relatively dull. It just makes the final 3-4 episodes incredible, but I'll never want to watch those weak ones again out of context.