I'll through my two cents into this hot topic... I too am a Quarter Horse fan, they seem to be less likely to kill you. I have had Arabs, too hot, all but Polish Arabs are too small, but they have rock hard feet, they dominate endurance riding. But all the Arabs I've seen are TOO HOT and crazy compared to Quarter Horses. Thororoughbreds are bred from Arabs, only real big...nuff said. Paints are Quarter Horses with color, but they seem to have their minor moments, but not a bad choice at all, the more white on a horse the more skin problems. Apps are hard headed, but not a bad choice, although not my choice. Morgans, ranch types are fine, saddlebreed types are too hot, going to Saddlebreds too hot. Remember, hot = crazy, crazy = your pain.
We have Quarter Horses and Paints, my wife has one nice in hand, crazy under saddle thororoughbred. We are knowledgable in some areas new to some areas of horses, always learning. But thats one of the fun parts.
Can't go wrong with a good Quarter Horse.
Just because I'm killing time, I'll throw in some advice you didn't ask for. Go with a Gelding, mares can have mood swings during heat, Stallions are dangerous if you don't know how to handle them and don't know what to look for when handling them. I would also go with a horse that is 8 to 16 yrs old, not too young to be crazy, not too old to be broken down.
And last of all if you go with a Quarter Horse check to see how much Thororoughbred blood it has, Some QH have a lot of thororoughbred in them (appendix Quarter Horses, i.e. racing Quarter Horses)
This may stir things up(?) Just my opinion
Alan