James Spader as Red Reddington is the answer and the sole reason this show is so watchable. He's not only the captain of the ship, he's the crew and the ship as well. In short, his performance is everything that makes this show great and I suspect he's somehow improved the template like performances of his supporting actors over time. The man is just a joy to watch and makes an improbable character--govt spy turned international criminal mastermind-- delightful and believable. Every actor on that show ought to thank Spader for allowing them the opportunity to make money on a show that would have been cancelled its first year--perhaps mid-season--if he were not on it. It's the darndest thing, the difference one actor can make.
Still, I wish that the creators had chosen a different actress to play the part of Elizabeth Keen, the FBI profiler that Red Reddington is inexplicably fond of. Someone like Zoe Saldana would have been brilliant casting and added dimension to the mystery of the Keen-Reddington relationship. And perhaps better casting for that part would have inspired the writers to shape her role more credibly and sent the show into the stratosphere. While Megyn Kelly may be a solid actress, she does not yet have the chops to make something of the oddly inconsistent writing for her role. Too late to change this up now.
I'm hardly the only fan who tunes in to enjoy Spader's performance, marveling at how the dreamy young actor with long blonde hair evolved into this very charming, balding older man who can act his *beep* off. I give him an Emmy for just Being There.