Draco in Leather Pants: Some people view Leopold too sympathetically. Even if he was only framed for killing Sophie, he had a reputation as an abuser and is rumoured to have murdered at least one woman already. Not to mention the little matter of him plotting to usurp his own father's throne.
Love to Hate: Rufus Sewell makes Leopold an utterly despicable bastard that viewers love most of the scenes he's in.
Magnificent Bastard: Eisenheim is a nice version (debatably), but really, can you call him anything else after the Gambit Roulette? By the looks of Uhl's expression, he's probably thinking the same thing.
Narm: The ridiculously goofy grin that appears on Uhl's face once The Reveal happens in the train station.
She Really Can Act: Jessica Biel's casting was met with a lot of raised eyebrows, all of which were forgotten as soon as people saw the film. These days, it is praised as one of her best roles.
Unintentionally Unsympathetic: The movie tries to make Uhl more sympathetic, as a police chief who is powerless to stop Leopold from committing his crimes. However he still meddles in Sophie's life, spying on her and reporting her whereabouts to Leopold when he has no need to. He also has no problem finding a scapegoat for Sophie's apparent death, and it's implied he covered up Leopold's other crimes despite being fully aware of them. He does not even bring Leopold to justice as the prince kills himself before Uhl can do anything.
The Un-Twist: Quite a few viewers had guessed that Sophie was not really dead, given that she's not seen being murdered.
Tear Jerker: The whole film itself is quite depressing, about giving up dreams and facing harsh reality but when Tatischeff releases the rabbit into the wild at the end tissues will be needed.
"Les magiciens n'existent pas."
The Sad Clown's suicide attempt (made worse by the fact that he's not shown again after leaving the hotel, so he could well have ended up killing himself after all), and all the scenes with the Ventriloquist in the latter part of the film. In the last scenes of the film, his beloved dummy is sitting in the window of the pawn shop marked 'FREE' and yet still nobody wants it, and he's begging on a street corner. And this is one of the lovable comic relief characters.