Season 1-3 are extremely good, if you want peak mafia themes. Season 4 is by far the worst (boring). Season 5 Steve Buschemi comes in and spices this up. Season 6 is pretty good minus the last 2 episodes. It's like they said screw it let's just end this thing. I hated the last episode, such a waste of a good shows potential. I'd recommend watching the whole show except season 4, it was just filler and not much going on.