I haven't seen that many. The old Saddle Club wasn't bad, though.
As for the WORST, I hated Flicka 2. Haven't seen Flicka 1, but the second one, all the kid does is cry and hate everyone except this horse (who is at least two or three, changes all the time) who she has a 'magical bond' with. Then she can pretty much instantly ride like a pro, and so forth...
I think lots of horse movies are actually made for NON-horse people so it doesn't matter if they get it wrong. They bug us, but hey, my friend enjoyed Flicka and didn't see very much wrong with the horse part (but also hated the storyline).
There's a place for everything in this world.