I wouldn't recommend My friend Flicka if you don't like Lassie type movies... It's the basic story [spoiler warning begins], a young girl, a wild horse tamed by her and then the girl and the horse save their family's ranch [spoiler warning ends]. Sorry AQHA if I 'stepped' on your toes, I admit I like that movie too, it's a good family movie and reminds me of magic of the horse crazy phase that almost evry horse lady has gone through once, when everything related to horses was purely amazing . I'd still personally consider it as a Lassie type movie.
The horse whisperer was pretty good one, tho the book was better. If my memory serves me, also Hidalgo is pretty realistic (perhaps based on true story at some stage, I'm not sure).