Mine would have to be the Thoroughbred! They are such honest horses, and they have an amazing attitude towards work! I love their long stride, their versatility, their speed, their agility, and the willingness they show when in training - they are just so obedient! They also make amazing outcrosses to almost any breed, whether to produce a riding club allrounder or a top sporthorse, you can't go wrong crossing to a good Thoroughbred. I love them most, of course, because they are in my opinion, the most beautiful of horses
I have one pure Thoroughbred, a young ex racer who I am retraining for dressage, named Piper, and an assortment of tb crosses. Here is Piper:
And here is a picture of my beautiful horse Fergus, who I lost to bone disease last year, he was only 8 years old :( He was the most talented horse I have ever met (eventing) and was a tb too, although had never raced.
These two horses have convinced me that Thoroughbreds are the way to go, if I am ever looking for another horse, I would always choose one!