Score

I just finishing reading Circlet of Oak Leaves by Rosemary Sutcliff, and I spent all night lying in bed thinking about how I forgot to add it to this specific list.
This book...! On the face of it, a 77 page (illustrated here and there) tale of war in 2nd century Britain (from the Roman's perspective). But underneath it is a story of suffering (long term), pride, failure, bravery, and character (over a lifetime). Basically, what it means 'to be a man'. To struggle inwardly, to be mocked (for years), to live with crushing guilt, to endeavour to become more than what you are/were...
It's slid very easily into my 'Favourites', and I'm not generally a battlefield/historical fiction sort of reader.
This is a great story for reluctant readers, early readers, etc. I'm middle aged and I loved it, too. :) I think it teaches resilience in a way I seldom see - instead of 'going postal' when you're bullied, this is the alternative: stoicism. There needs to be more books like this (and thank you for this list, sharing the good 'uns!)
Long out of print, but you can comparison shop on bookfinder.com for used copies. I picked up mine at a local secondhand bookshop for 1.49 :)