Which breed of horse is best for English riding?

Well, from your list I would select Thoroughbred as the #1 most likely to be a talented English mount, but any horse if it has the proper, consistant training and miles can show potential there. Nothing against them, but I haven't seen a large amount of successful Appaloosa English horses, but thats not to say they can't....maybe thats more of a shot against the people working with them, idk. I would think Dutch Warmbloods, hanoverians, Trakehners and Oldenburgs would be really good English horses, but as for me in real life most of the horses I have ridden are Quarter Horses or Appendix's, like my horse. They seem to have perfect disposition for English.

Really, any horse can be ridden and used for English riding- Sure, some do better than others at it, but any horse can do it to some extent. And generally at the lowest levels you see a total mix- Appendixes, Apps, Mutts, everything. However, by the highest levels you see mostly Warmbloods (Such as the Hanoverian, Trakehner, and Oldenburg), TBs, and Anglo-Warmbloods (TB x Warmblood) . Sure, there are exceptions, but you don't see a Quarter Horse at the Olympics. Between the upper and lower levels, you see a mix of those, with the proportions shifting as you go up or down. If you go by discipline, and by those recognized by the Olympics, you mostly see various heavier Warmblood breeds in Dressage, lighter, more "Modern" type warmbloods and Anglo-Warmbloods in Show Jumping, and OTTBs, TBs, and Anglo Warmbloods in Eventing. Honestly, what makes an English Horse a good English horse is conformation and movement, and that's why many of your best Western horses would do terribly in the English Disciplines and visa versa. The stout, downhill build and choppy movement of a Quarter horse, even a champion one, would make it a failure at anything but the lower levels of Dressage or Jumping, where having an uphill build is extremely helpful and you want floaty gaits with lots of suspension. On that note, enter a Dressage horse in a HUS class (Which is really just WP in English clothing- It's nowhere near even real Hunters) and it'll get dead last.

Any and all of the horses you've listed can be used for English style riding. Having said that, different breeds are more suitable for specific types of riders and disciplines than others.

Most of the horses you listed can be classified as "warmbloods" which make them idea overall horses for hacking, jumping, dressage, eventing, etc. The horses like the Shagya Arab and the Hackney are smaller and lighter breeds and would be better for hacking and riding on the flat. Quaterhorses and Canadian horses (the northern cousin) are generally considered good breeds for a variety of disciplines, though you don't see them in competitions requiring jumping and will more likely see them in Western-style riding.

It depends on if you're jumping (and doing Grand Prix level) or doing hunter hack type stuff, just flat work like equitation classes, cross country, or dressage. Some of those horses are better at different things.

I prefer a Quarter Horse, or Appendix Quarter Horse. THe appendix still have some Thoroughbred in them, usually makes them big scopey movers, but I love the level-headedness of the QH's.

Aw, quarter horse isn't even on your list! Anyway, I know TB's are used a lot in tthe show ring. But in truth, the best horse for English riding is a well trained horse, which could be any breed.

Any horse that is well trained. Breed has very little to do with it. Granted, certain breeds are more common in certain disciplines (warmbloods in dressage, thoroughbreds in eventing/jumping, etc.) because their physical characteristics suit the demands of that discipline. But, a highly trained clydesdale would do better in dressage than a warmblood that is barely saddle-broke.

well it really depends on the horses training. a thoroughbred is most commonly used. i have also ridden Arabs and quarter horses that have been great in english riding. it really depends on how the horse was trained, and on how it's gait is. some horse are just born with slow steady western gaits, and some horses are just born with a faster stride.i hope this helped!

Any breed can be trained to ride english style of riding.

Itr depends on the person,the situation,what your doing,etc. A hack pony won't do well as a dressage horse. It all depends.

None or all, depending on their training. Some are more well-known than others (for instance, WBs in dressage) but that doesn't mean that the others can't do it.