Stunt Casting is when shows pick high profile actors for roles which generate media buzz and thus some free publicity. The Simpsons and Will & Grace are/were great at this. But the life-time achievement award in stunt casting has to go to Smallville which continually picks actors from past Superman movies and shows. This started from the beginning with Mrs. Kent played by Annette O'Toole who played Lana Lang in Superman III. They continued with Terrance Stamp (Superman II's Zod) as the voice of Jor-El, Christopher Reeve as Dr. Swan, and Margot Kidder (Lois Lane in the movies) as Dr. Swan successor. Although after a couple episodes she was found murdered because the actress is koo-koo-bananas. Recently they had Dean Cain (from Lois and Clark) as the Immortal. He was captured at the end but since he is immortal he can easily return. Tonight Clark meets his Krptonian mother (or some sort of Fortress of Solitude clone of her) played by the actress who played Supergirl in the 1984 movie I didn't see.
Here's who I'd still like to see: Ned Betty, Gene Hackman, Susana York (Kryptonian mom from the movies), John Shea (Lex from L&C), Traci Scoggins (Kat from season 1 of L&C), and of course Teri Hatcher.