I do have a fondness for Joker, especially Heath Ledger's Joker, just because he's a menace to everyone. Batman, the police, citizens, even other criminals. He only picks his side, and knowing the Joker -- that side changes a lot. He's based on whims, but there's a method to the madness, so I'm hard pressed to believe he's entirely insane. He just knows how to work the angle.
I kinda go into it knowing that what he does and how he thinks isn't all that good (it's REALLY not all that good). I know they've tried to create a sympathetic arc for him before, but I personally think he doesn't really need one. Given his character, it wouldn't change my perspective of him and I doubt it could reasonably justify what he does. Kinda hard to go "awwww" or "I get him" when he can easily force someone to choose between killing their loved one to save 20 people and vice versa. 
So I'm kinda happy they played around with it, adding more complexity to his character. Is he actually telling the truth? Is this just one of his many acts (he IS a clown, after all, and clowns know how to perform)? Maybe it's both, but with how Joker spins himself and his motives, we truly never find out for sure, and that's what I like.