Quotes: Anti-Climactic Unmasking

Harley Quinn (re: the captured Batman): Ain't you gonna take his mask off and find out who he is?
The Joker: And reduce my primal enemy to a mere man? Harley, dear, I'm so disappointed in you! Where's the fun in that?
Batman: The Brave and the Bold, "Emperor Joker!"

Lex Luthor (having swapped bodies with The Flash): If nothing else, I can discover the Flash's secret identity... (removes mask) ...I have no idea who this is.
Justice League Unlimited, "The Great Brain Robbery"