Crossroads Farm is an excellent hunter-jumper barn with a trainer owner (so emphasis is on riding and horses instead of profit)! A wide range of riders who have everything: ponies, quarter horses, thoroughbreds, and warmbloods.
The prices are excellent, too. I was surprised to find a barn within 30 minutes of the South Mountain area that is reasonable with excellent training and a fun, down-to-earth crowd.
http://www.crossroadsfarm.com/