The pros for Breaking Bad is that it does just about everything better. They have American actors playing Americans, as opposed to Andrew Lincoln (the guy with the poster cards from Love Actually) trying to do a southern accent on Walking Dead. The scripts are better, with symbolism and themes and everything. The show is slower to start than Walking Dead, which does excellent premiers and finales, but is more consistent and builds to better and better stuff. It is one of the very few shows I watched that got more... confident, for lack of a better word, as it went on, and got better at telling its story. The Walking Dead hit some high notes from the outset, but could get plagued by slowed-down storylines and narrative stalls. Breaking Bad got better as it went on. They didn't stop when they ran out of story, they went to the end and stopped. The only other show I can think of that kept getting better and ended on a peak like that would be "The Shield." The last season of Breaking Bad contained some of its greatest episodes.

For the most part, the Walking Dead does excellent action and horror stuff, and has great zombie effects. It can get some genuine scares and is pretty good at atmosphere. Breaking Bad doesn't always do action, and has very little in the beginning, but when they do go there, it works well and is earned. While the characters are seldom in the sort of danger or peril The Walking Dead does, it tends to be really suspenseful because of the kinds of real-world dangers they face. By the mid point of the series, they've really stepped up their game on the violent scenes, which were initially over-the-top (but intentionally so, highlighting how out of their element the lead characters are).

For characterization, the cast of Walking Dead is sometimes transient, and the supporting characters are often neglected in development, with just a couple of stock traits. That gets a lot better when they start making an effort to correct that in season 4 (Season 6 is currently on the air), but even the more consistent characters seem to be shaped for an open-ended series, without getting definite arcs. The hero undergoes changes and adjusts to his world and circumstances, but he's also the hero of a wildly successful TV show that they want to run as long as they can. Breaking Bad has a smaller cast, whose initial group is pretty much the same, with a couple of additions here and there (most of whom turn out to be very welcome), and are explored and fleshed out in the context of the hero's growth and changes. As you might infer from the title, it is the story of an ordinary, boring dorky milksop into something much more. Or in another light, the emergence of his true self from the role into which society and his life choices have constrained him. Walter White has a clear arc, and his characterization is in service to that arc. Rick Grimes, not so much. That has its own benefits, don't get me wrong, but Breaking Bad knew what it wanted to do and did it well.