I've stayed out of this thread because I didn't watch the show until end of last year (plowed through it all). Damn good entertainment. The series premier really did it for me. The opening five minutes with Cranston blasting across the desert in his tighty-whiteys and gas mask with three bodies sloshing all over the Winnebago sold me on it, where I initially wasn't sure if I'd be interested in it or not, given the premise.
What initially got me interested in it was something I read from that Gilligan fellow about his idea for Walter White. He wanted to take a normal, likable fellow, and see what would happen if he had to turn into a bastard. How would it work? How long would the audience support him before turning on him? Tony Soprano, who kind of started the likeable bad-guy television persona, was always rotten. You liked him, but you knew from the start that he was something of a monster. In this case, Walter started out as a good, honorable guy with reasonable intentions, but turned into a real POS so gradually that nobody really noticed when it happened. I can say that in my case I found him despicable well before the first season ended, but even then he was still occasionally sympathetic. Fascinating thing, really.