RDR features the best horse riding experience imho. Yes, it might be a little realistic when it comes to steering but I think that was part of the design. Assassin's Creed features the hoppy horses which is really painful to watch, yes these horses turn left or right on whim but you never are immersed when riding.

I realize that the gameplay is repetitive but honestly, repetition is part of modern games especially action rpg's. I feel that the devs really did their best in squeezing out every exciting bit of action in a deserty, low-tech, low population environment. I really felt that people back then really were sitting on their hands.

Story. Now I did not grow up wanting to be a cowboy or an indian or a bandit. Yet, I did appreciate the story to a certain degree. It was a little bland based on the contextual games that came out during that year (Fallout New Vegas, Mass Effect 2, Starcraft 2) but still, it was seasoned a little better compared to the blockbuster ones.