Clinton Anderson!! I've seen Clinton three times at his Walkabout Tours, have his book and several dvds. His no fluff, black and white, tell it like it is way of teaching really clicks with me. I can easily understand his methods and put them into effect with practice. I've seen these methods work really well with our horses and enjoy using them.

I'm going to date myself but years ago when John Lyons first started clinics, well before he was published he was good just common sense stuff.
As for riding, just did a clinic with Colleen Kelly from Australia-AWESOME
Denny Emerson-A favorite I ride with him as often as possible.