Sometimes a comedy role is such a perfect combination of casting and performance that it's unthinkable for another actor to ever attempt it. Here are the top 10 roles that could never have been and never will be replaced.

#10. Anthony Michael Hall: Weird Science

There are three main types of movie nerds. One is an academic stereotype who doesn't talk much. The second is a hilarious weirdo who would be totally popular if he wasn't in a movie script. In Weird Science, Anthony Michael Hall perfected the third: the nerd whose sexual frustration has driven him insane.

Continue Reading Below Advertisement

Hall performs in Weird Science like his captured family will be killed if he's not funny. He packs more manic desperation into his lines than a dry-humping seventh grader. He delivers lines in ways that would make Christopher Walken say, "What a strange WAY to deliver your lines."

To be fair, almost every casting decision in Weird Science is irreplaceable. Bill Paxton will never have a more perfect role than Chet, and even after 25 years of filmmaking, this is still Robert Downey Jr.'s greatest moment: