In The Dark Knight the Joker kidnaps Rachel and Harvey Dent. He then tells Batman he'll need to choose who to save, and gives him two address:
He's at 250 52nd Boulevard. And she's on Avenue X at Cicero.
Just after this Batman declares his intention to save Rachel and he and Gordon race off to the indicated addresses. However, when Batman gets there, Harvey is the one at that address and Batman saves him instead.
Although I certainly wouldn't put it past the Joker to intentionally mislead Batman and show him where his weaknesses lie, he also likes to play it loose and might have left those details up to his henchmen.
Is there anything to indicate whether this was an intentional misdirection on the Joker's part, or if he was simply ignorant of who was where?