I recall only two shows with a Halloween theme, My Name is Earl and Jimmy Kimmel Live.
Maybe a few more that I don't watch had something but TV-wise it was really weak this year. While on the streets in NYC half the people were dressed up mostly in homemade costumes.
I saw alternative energy, one girl was corn, another was solar-panels, and the guy held a fan and was wind energy.
I saw only one political costume and it was a guy holding a plunger with a name tag that said Joe the Plumber.
On NY1 the sea of hundreds of thousands only produced 2 Sarah Palins, yet a few dozens storm-troopers.
My favorite was the two Wookies and the Original Ming the Merciless.
P.S. Jeremy S. thanks for link but this blog is about TV not Movies and about shows not celebrities. Also my last tribute was to Bernie Mac please google him to see a picture of what he looks like.