Wow, I haven't read quite a few of these! I must find Code Name Verity and Crown Duel!

I forgot to vote (tbh I kept putting it off because it was too hard! lol) but I would have cast a second vote for Huckleberry Finn and a third for His Dark Materials. And a fifth for Harry Potter. Although, like others have said, HP hardly needs to be stated.

And QT, of course.

It's the fifth that's hard. I can come up with a top ten list, but where does the cut off go? Agggh!