Aw, dude. Peter Falk as Columbo? Lucille Ball as Lucy? This is a truly great cast, but I'm not comfortable with calling anyone in history the #1 greatest.
Like you said on the rest, agree to disagree. But like I said, I'm one of the few folks who actually loved VG's Lone Gunmen spinoff series. I'm hardly saying that the show succeeded in spite of having him as the showrunner, simply that I feel Breaking Bad wouldn't be remotely what it is today if not for the contributions of many others at various levels.
In other words, take BB with VG and put in, let's say, the Law & Order SVU writing/directorial staff, you don't get one of the best shows of all time. One final point I'll make with VG - this is the dude who wrote Hancock. You know, that godawful Will Smith movie? (If you loved Hancock, apologies.)
Now as far as the casting, I feel pretty confident in saying that. First and foremost, I cannot picture any other present day actor approaching what Cranston has done. His appearance alone just gives off this remarkable Jekyll and Hyde where one minute, loving family guy, put on a top hat and suit, baddest muthafreaka in history. Good lord, this is Hal, from Malcolm in the Middle. Stunning, utterly unique and historic transformation.
Then his acting chops - incredible. His most known role beforehand was from a family comedy, and whike he did some dramatic parts, seemed to be, for the most part, known as a comedic actor.
Lucille Ball largely played herself. Not exactly a stunning transformation there - hell, in most all things she did she played one goddamn role. Further, there wasn't the vain, surface 'appearance' thing quite as much as with Cranston/Walt. DVD covers, promotional posters - when they portray Walt as the evil badass he is, it comes through in just still photos. He's literally scary looking.
Have there been a ton of great casting choices over the years, where an actor came to symbolize a particular role? Certainly.
But three factors separate them from Cranston - first, I don't see any other modern actor being able to approach Cranston as Walt. That saying gets used a lot with iconic roles, but here it is particularly apt. Especially with the dichotomy of Evil Heisenberg, lovable Walter White, family man - having me *still* rooting for him despite all he's done. Like I already mentioned, Hamm and Gandolfini were great. But you don't like their characters, with Don Draper far more of a saint than Walt ever was. That Cranston can pull that off is amazing. Then lastly, there's Cranston coming from an entirely different genre/character set and completely owning the dramatic villain role from day one. Ball and most others had careers beforehand mastering their craft. Cranston just made the craft his nag.