First and foremost, if you aren't watching Breaking Bad I suggest you start immediately. The finale for Season 4 was about as compelling as you can get. Don't even visit the official site if you've not watched the show, you're better going in totally ignorant; promise.

If you have watched the show and you're all caught up I suggest partaking in the following extra bits of media.. because there's no such thing as too much Breaking Bad.

• Vince Gilligan Season 4 Walkthrough - the AV Club sat down with creator Vince Gilligan to discuss every episode in the latest season. Part One and Two have been posted with the following two installments following during the remainder of the week.
• Bryan Cranston on WTF - Marc Maron gets a lot of information and history from Bryan Cranston in this episode of WTF but they also talk a great deal about the formation of Breaking Bad and, ultimately, where it is headed. No specific spoilers, more of a broad thematic goal.
• Giancarlo Esposito Interview - any insight into Gustavo Fring is good insight.