There weren't supposed to be a 5th season from what I heard. It's still an amazing season though. Unlike The Walking Dead, Breaking Bad doesn't go down much in quality in certain episodes as the story evolves. They're all great with barely a few slower ones.
Walking Dead's season 4a was kinda lame, it felt like a re-run of season 3b. You don't have to endure such a thing in BB.
I'm on season 3 of Walking Dead. No spoilers, please!

Breaking Bad was amazing to the very end. I like Fargo, too. Wondering how season 2 will be.