Really, I think it's the characters and their interaction. I've mentioned before how various shows are what I envision larps as. As really, Deadwood is an almost *perfect* larp show. Almost every character is very important. They're all interconnected in this gigantic web.
Something else I noticed early on was this concept of 'managers' that the show has. There was a few big movers, and their subordinates. When they wanted something done, they had a subordinate do it. Al wouldn't go whack someone, he would send Dan or another lackey. Cy Tolliver's entrance was so grand because he brought a new element into the mix, complete with his own subordinates and all their motivations, etc. And now, with Wild Bill gone, we have to see how his subordinates (Jane and Charlie) we get to see how the show changes with one of the managers gone.
Plus: Powers Boothe *and* Brad Dourif? Sign me up! Let me also say, the chick who plays Jane is a real treat. She cracks me up every time she's on screen. Keith Carradine was so impressive as Wild Bill, because (probably due to his Carradine Western DNA) he carried such a charismatic presence to the role that you just have to watch him when he talks.
Character-wise, the preacher is another fave. He's just so *weird.* Also, Eddie (Tolliver's right hand man) is big fun. "Speaking only for myself, I still mark the anniversary." But really, I have new favorites every week, mostly because everyone is so well-written.
But why the heck does Merrick (the reporter) sneeze so much every time he's in the graveyard?
Anyways. been meaning to get this off my chest for a while.
[Not too spoilery, in general, but you've been warned.]