But I've heard that Deadwood doesn't have a satisfying ending while SFUs end is supposed to be great.
The back half of Deadwood's entire 2nd season is a let down. I loved Season 1, but through Season 2 my love diminished till I regretted sticking with it.
I would also choose SFU over Deadwood.
The West Wing is the best of your choices, but I understand the commitment required, and I'm too busy to join you in a West Wing marathon right now.