My wife and I own 4. Two old saddlebreds, my wife keeps at her parents farm. The one mare is going to be 30 this year, the other is in her early 20's Basically they are pasture ornaments my mother in law likes to look at.
We've got a moderately high dollar quarterhorse (Doc Bar/Poco Pine blood line) who was a rescue. She was diagnosed with EPM when I was in veterinary school. My wife convinced the owners not to euthanize the horse, but rather to donate it to the school, where we bought her back for $100. That way the owners got their insurance money, we got a horse, and the horse didn't get euthanized. She's a great horse. A little neurologic, but a great horse.
The final horse is an 8 year old off the track thoroughbred gelding. He's big, dumb, and fast. He was donated to the university as a research horse when he was retired from the track because of laryngeal paralysis. The owners donated him, where he was part of this reasearch study on a surgical technique, my wife fixed his laryngeal paralysis and adopted him after the study rather than euthanize him for the study---she worked hard and got all of the research horses from that study adopted instead of euthanized. Like I said before, hes dumb as a rock, but he's a good horse.