Honestly, the Joker's socks take the cake. It's such a small detail, but they're just so hilariously bizarre - fits him perfectly. Not sure whose idea it was for him to wear wacky socks like that, but kudos. I hope he wears them throughout the whole film.
If they aren't taken down by now, you can see in the left pic (where Joker is kicking Bats) that his hair is barely green. In fact, it looks like he's only dyed the very tips of his locks, which fade into brown. The other "knife" pics (with Rachel) confirm this. Yet we have the IMAX pic w/ Nolan, in which even through that weird glass, his hair is much greener (and green pretty much all over), and in the newest one, his hair is almost totally green-looking. I realize the newest pic has a green tint to it, which would manipulate things, but his hair isn't brownish at all - it's obviously green, and greener than in the leaked pics.
Strange. Either his hair is dyed shock green at some point and continues to fade throughout the film (i.e. he only dyes it once over the course), or something else entirely (are his methods supernatural? j/k)
In any case, even though there's no evidence at all for it as this point, I like the idea of the Joker basically having several layers of makeup on. It's weird, bizarre, and totally Joker-ish, in my opinion. For example, what if his hair was really green - then he dyes it brown, and then using some kind of cheap staining material (like food coloring), he dyes it green on top of that. His hair would continually "run" throughout the film - from green to brown back to green again - mystifying our heroes and the audience alike. People would wonder how the hell he has this trippy, two-toned hair that changes from day to day, not realizing until the end that's it all a ruse.