When BE first appeared in the trade papers I remember people questioning whether Steve Buscemi could carry an entire series as did the late, great James Gandolfini. I think he has proven beyond a doubt that he is one INCREDIBLE actor. I ordered this Season because I somehow misplaced (lent?) it to someone and so had to replace it. I have seen the entire 5 seasons and each one was a winner: great characters, great performances, incredible sets and camera work, tremendous writing, brilliant directing. Some of the actors took a little taking used to, especially Vincent Piazza as Lucky Luciano, Steven Graham as Al Capone and the actor portraying Bugsy Seigel (sorry buddy,, your name momentarily escapes me). A NY native (via Brooklyn) I found Piazza's "Newyorkese" a bit too exaggerated with it's sibilant "s" but over time grew to rather enjoy his increasingly nuanced performance; I've heard Piazza in other films and with the exception my earlier criticism, thought the manner in which he modulated his voice quite commendable. I was ambivalent about Steven Graham's performance of Al Capone which was quite over-the-top; granted Capone was addicted to cocaine, was suffering from what would eventually become tertiary syphilis (while being treated in a way today which would have been deemed malpractice and was the actual cause of his death) but I doubt he was that much of a clown and that off-the-wall to have survived as long as he did as Public Enemy #1. You don't rise to the top of that heap by being a dolt.Ruthless, vicious, Yes. Out of control, irrational, no. He stayed on top because his men feared him and they would not have feared someone they felt was crazy, outlandishly narcissistic as he is portrayed in most of the episodes. Along with their fear there was also a certain amount of respect for is position. these men don't want a "cowboy" running things I pretty much found Graham's Al Capone to be the same performance he gave as Baby Face Nelson in "Public Enemies"" and yet, as the series went on, his family scenes especially with his deaf son, and the one when he tells Jimmy that his son can't hear him when he plays the mandolin and sings to him, having need to touch his throat but never hearing the sounds were quite touching. I found his final scenes provided a balance to his earlier ones when resigned to his fate, he "plays the role" for his public while realizing it's only his farewell moment of "Glory" and his slight nod to the undercover cop who brought him down an admission of respect and defeat. Nice touch.
I also doubt that Bugsy Seigel would have ever survived as long as he did if he were ever the eternal juvenile; they simply weren't tolerated by those who controlled organized crime in the day. I also doubt he had that whiny voice. He was called Bugsy because he was psychopathic with a hair-trigger temper, a lot like Abe Reles, so I found his characterization unbelievable however that is a question of interpretation and doesn't mean the man is a poor actor as much as it was the way the role was conceived by others.
As for the rest of the cast, just as in "the Wire", "The Sopranos" and "Godfather's 1,2" and "Goodfellas" what makes these series and films so great aside from what I mentioned above are the other supporting actors and brilliant character actors and this entire production from Series 1-5 had an abundance of these: Kenneth Williams, Kelly MacDonald, Michael Pitt, Gretchen Moll, the various children...all too many to mention but each one perfect in their roles. Boardwalk Empire? ONE OF THE GREAT ONES.