Red Dead Redemption 2
Rockstar’s Red Dead Redemption 2 arguably has the most advanced horse riding of any recent game, and the best level of detail on the horses in any game today.
Similarly to bonding in Breath of the Wild, Red Dead Redemption 2 has a horse bonding/leveling system.
Increasing this bond can increase health and stamina, allow you to navigate deeper water and tougher terrain, whistle your horse from further away, and your horse will be less difficult to steal.
There are 19 different breeds, all of which fall into different categories, including riding, superior, war, work, draft, and race. These categories impact aspects like health, speed, acceleration, and stamina.
Horse items such as saddles, stirrups, and saddlebags also make a big difference in how useful and convenient your horse will be.
As mentioned, Red Dead Redemption 2’s level of horse detail is borderline ridiculous but is definitely commendable. Rockstar even went so far as to make horse testicles shrink when enduring cold weather.