As Johnno pointed out in an earlier comment, The Simpson's annual "Treehouse of Horror" is always worth a watch. The writers do an absolute top-notch job of ripping off every iconic horror thread - Poe, Stephen King, Rod Serling - and it makes the segments 'way funnier and more brilliant if you're familiar with the original source. Plus, they do funny things with the titles. Here's a guy who gives his opinion on the top 5 ToH episodes. Who can choose just five? Can you leave out "House of Whacks" or "Hex and the City"? Grab a Duffs and a bag of candy corn and enjoy.
The Connor family of Roseanne-fame knew how a solid, loving, mid-American family should celebrate Halloween. It was kind of a cross between Halloween and April Fool's Day, with everybody trying to out-scare everybody else. The parties! The costumes! The fake blood! A real family holiday (in comparison to the disastrous Thanksgivings and Christmases they shared). The Roseanne Halloween shows have been compiled on DVD this year. Not trying to sell you anything, but if you scroll past all the Amazon money-grabbing information, you'll find a good list/synopsis of the episodes. Sure to bring back fond memories.
What other sitcoms have good Halloween episodes (not counting The Addams Family and The Munsters)?