I would deffinatley say War Horse it isn't long but it is truly amazing.. It's about world war 2 in the eyes of one horse. Ahh it's my favourite!!!!! Posted via Mobile Device it's written by Michael morpurgo.. :)
My friend flicka, thunderhead, and green grass of wyoming I think were my favorites. Although I couldn't get enough of the Fury of broken wheel books....
I love the Misty books and infact have reserved our hotel and boat ride for next summer to see the swimming of the ponies....
I also love Centered Riding.... it is old school but gives fantastic mental pictures on being balanced. I also like The Tao of Equus by the author listed on my signature. I also like How to Think Like a Horse by I don't remember his name.