Show: I Love Lucy (CBS, 1951-1957)
Character: Ricky Ricardo (Desi Arnaz)

This is the greatest television quote that the character never actually said. Desi Arnaz is famous world wide for portraying the straight man to the legendary Lucille Ball. When Lucy got herself in trouble, Ricky would always be there, hands on hips, looking for an explanation. Ricky would often ask Lucy to "splain," and phrases like "Ok, 'splain," and "Alright. Start 'splaining," weren't uncommon. But Ricky never said "Lucy, you've got some 'splaining to do!" once during the run of the show. It's widely thought that a journalist must have misattributed the quote toward the end of the series run, and from that point forward, the catchphrase that wasn't was forever committed to history.