My Horse & Me: Riding for Gold
In this game, you can choose a horse of any color and care for it, train for shows (jumping, dressage, cross country) and enter worldwide competitions.
This game has an inspiring story about a girl who goes to live with her Uncle at his ranch during the summer. But the horses become sick (I won't tell you who made them sick because that will ruin the whole story.)
All in all, a very good game.