List from Encyclopedia of Fictional People:

Robocop (Robocop)
Tattoo (Fantasy Island)
Inspector Jacques Clouseau (Pink Panther)
Steve Urkel (Family Matters)
Herman Munster (Munsters)

Have any to add? I do: Jon Arbuckle (Garfield) and Louie De Palma (Taxi). I mention Louie not because of his height, but because he'd be trying to cop a feel the entire time!! :eek:

Kramer & Elaine from Seinfeld would probably be a nightmare to dance with too.

Robert Barone- Everybody Loves Raymond

Vicki Lawson - Small Wonder

Jan on BB said that Alice was a really bad dancer.

Lurch - Addams Family

Gilligan would probably be a nightmare dancer.

Dr. Gregory House - House

JJ Evans - Good Times

Cindy Snow-Three's Company definately a dance partner nightmare.
Chrissy Snow-Three's Company
Skippy-Family Ties

Mr. Carlin
Mr. Herd
Mr. Peterson - The Bob Newhart Show