Ranking and favorite are different for me.
Parks and Recreation-My favorite because Leslie Knope is a hero for our times-she is smart, driven, enthusiastic, unrelenting, supportive, cares about her tiny corner of the world, endearing through the annoying. I love her so much. I love this show for his goodheartedness. It has some of my favorite characters in sitcom history. Until it goes off the rails, I love how small it is.
The Office
30 Rock
Community-I like Community. I guess I rank it last because I find it a little cold? Other than maybe Troy and Abed's, I never found any friendship or relationship on this show to be particularly close or warm or have any depth to it.
Besides being talented, Dan Harmon is also a bit insufferable and tough to take. I think the association has subconsciously bled into my memory of the show.
Finding out recently that he's also a tremendous creep wasn't fun, either.