According to Radosh, who has audio to prove it, a very good modern answer on Jeopardy got rejected in favor of a deeply obsolete one:

Jeopardy champion Ken Jennings is robbed of $200 when Alex Trebek rejects his response to the clue, “This term for a long-handled gardening tool can also mean an immoral pleasure seeker.”

Jennings had said, “What is a ho?” The “right” answer: “What is a rake?”

Thanks to Eugene Volokh for the link.