This is how I see their first meeting:
It's a darkish warehouse, akin to the first drug bust in the Begins, but more industrial. Batman is walking on the floor scoping things out, maybe with Gordan at his side.
Joker (off screen): A boy in a bat costume and an old man in a dective's costume. How enthralling!
Batman: Show yourself!
The Joker is up in the metalic rafters, almost dancing around them, like a cat, incredibly nibble. He almost falls off but catches himself.
Joker: Hehehehehe, two left feet. So whatcha guys up too! Did ya get the card I sent you? You can never trust the postal service these days, always snooping through the mail! I'd be surprised if anyone gets anything I send them.
Batman: So you're the clown.
Joker: Last time I checked I wasn't dressed as a bat. Comparitively speaking, I'm pretty freakin' normal compared to you Batsy! {laughter}
Batman: Who've you killed!
Joker: Oh boy! Well, just this morning, I gutted a really ****ty comedian, I mean he was b-a-d. Then I had brunch, some toast with a granola bar, orange juice, it was wonjderful. Then afterwards, I don't know if you heard about this or not, but I gased a schoolyard. It would have been all over the news if it weren't for the so called, "Masscre in the Mall." Oh wait, that was me. {laughter}
Batman: You're insane.
Joker: You know, you're cute, not physically, I don't swiing like that Batsy, don't get your hopes up there. You know who is cute though, that little District Attorny, that's ever so popular these days. Mrs. Dawson I believe, yeah, she was pretty cute. Until I cut her ear from ear.
Batman: Rachel!
Joker: You knew her! Oh boy, looks like I've made an enemy. Well Batsy, in the back room, I left you surprise. Oh and Gordan, give my regards to the daughter. {laughter}
In the back room, there are about 40-50 gruesomely smiling workers. On the wall there is a smiley face, except it was white, with green eyes and a red smile and written under it, it says "SMILE."