17. Katy Perry's Breasts - (S22 E8 -"The Fight Before Christmas")
If you haven't watched The Simpsons, say in the last 15 years, this is not the one to come back to unless you want a healthy dose of WTF happened? Breaking their more traditional formula by having story segments instead of a continual plot (Treehouse of Horrors excluded), this Christmas themed show - which ended with a Simpsons live-action Muppet style with a canned laugh track and corny jokes - was pretty bad. Then Katy Perry shows up as Moe's girlfriend in a latex Simpsons dress and sort of sings a Christmas carol, and it's a bit much. Apparently producers of The Simpsons decided to invite Perry to milk the controversy she stirred up when it was decided she was too buxom for Sesame Street. See? Cultural relevance!