Initially I enjoyed this show a lot and looked forward to it weekly. As it has gone on the raunchy humor for the sake of being "edgy" has started to wear thin, but then there tends to be an episode that reminds me why I love it.
I'm not sure that it's fair to have to rate all of these seasons as one show. I loved the first season, enjoyed the second season, never finished the third season, and so far am not disappointed with the fourth.
To me, this show is the perfect sitcom.
I enjoy the characters on this show and how I like and dislike them almost equally. I think the writing makes them very human in their imperfections.