My Most Excellent Year by Steve Kluger
Again, I have a different cover. What gives, Amazon?
Anywho, I read this book in one day and LOVED it. It had some quirks I don't normally go for--like adult voices in a YA novel--but the way they're presented, as ephemera I imagine the kids coming across and maybe even posting into the journals the story is made up of, works.
Plus this book had two key elements I'm passionate about in YA fiction: LBGTQ issues and disability. The disability isn't even alluded to in the back-matter, which almost impresses me. The little boy who is deaf in the book is just another kid, granted with a tragic past, who happens to sign and read lips (very efficiently, except when it works for the plot, but still).
It has theatre, French, Julie Andrews and Boston. The voices are unique, the kids are endearing and I really connected with the era. It takes place in '03 and the main character's birthday is five days before mine (as in, February 16th, 1989, literally five days before my birth), so I think that helped me connect too. The characters are intelligent (!) and witty.
This book is what I most want to see in YA novels.