Ive hardly found any, the best (and IMHO the only one worth reading) being Michael Hassan's crash and burn.
Are there any other good Young Adult or children's books with ADHD main characters that I'm not aware of?
(I'm referring to books where the main point is the story, not where the story is basically "Billy overcomes his ADHD")

[SFP]

The Rick Riordan Percy Jackson series although I'm not sure to what extent the ADHD is represented as fully as it might be. You might consider it a fictional device rather than a true representation. The books are good though.

yeh ive read those. not very realistic portrayal. Sara Pennyparker's Clementine series (for younger kids) is far better

Well the Percy Jackson series isn't actually ADHD, its his demi-god inherited memories/instincts type deal that normal people THINK is ADHD and dyslexia.