Charlie Kaufman has probably been the most interesting person in Hollywood over the last 10 years.
Being John Malkovich is the only one I would classify as weird, in so much as its large amount of absurd surrealism.
Adaptation is brilliantly clever, and I think it does a great disservice to the film to use the adjective weird. Certainly, the two parts (screen writer with writers' block, and orchid hunting) are by themselves unremarkable, with its brilliance coming from how Charlie interwove the two.
The Eternal Sunshine of the Spotless Mind, using a science fiction device to study the power of love, is no weirder than the premise behind something like Minority Report or I, Robot.
After Eternal Sunshine, he made his directorial debut with Synecdoche, New York. If you thought describing his previous work was difficult... It's fundamentally the story of a theatre directory who creates a giant recreation of his own life. Except it's not really a movie with a recognisable traditional plot arch. Its certainly wasn't a commercial success (so its unlikely he's sat counting his money), and divisive with the critics.