The original Batman movie is not the one with Michael Keaton.
The original Batman movie was made in 1967, and featured 4 supervillains (the most in any Batman movie).
It also featured the Bat-Boat and Bat-Cycle. Ooops…got off track…
You could see DK as a standalone. Just understand that Rachel was the girl next door (when Bruce Wayne was growing up)and she knows who Batman is.
Heath Ledger’s perfomance as the Joker is stellar and worth the price of breaking the seal.
He isn’t manic like Cesar Romero’s version
He isn’t a bad-ass psycho like Jack Nicholson’s version