Roseanne and "one big laugh"

So far in my big sitcom project, I've figured that if a show can give me one big laugh, one that feels earned and true to its characters, it's worth sticking with for a while. Mary Tyler Moore and Cheers both did it in their pilots, but Roseanne took until the end of its fifth episode to really get to me. I've got a few problems with the show at this stage (mostly regarding Roseanne's acting abilities and the hooting-and-hollering audience), but I think I'll be happy to stick with it.