But I think my "favorite" programming teachers have been the ones that were at or just above my overall programming skill level. The point here is parity. I'm a fairly average programmer.
Often during classes, when I finish the classwork, I like to engage in a little extra credit and explore oddball ideas. If the instructor was at a similar level to me, the enthusiasm would often be contagious and rope them in. Sometimes this would turn into longer term projects. I always enjoyed that human aspect of programming.