I had the same initial reaction to "Boardwalk Empire"
It's very slow at the beginning and I also wasn't sure whether Buscemi was right for the role. However, by the end of season 1, the show and Buscemi had both won me over. And season 2 is even better. Those first 2 seasons as a whole are up there with the best TV drama I've seen. A modern day Greek tragedy, really. But if it's not really your type of show anyway, you might not really have the patience it requires (at least at the beginning).
Keep forgetting about "The Americans". Gonna have to check out that one as well (assume it's on Hulu).