A couple other legendary names who left in time, that is while at (or near) the top are Ara Parseghian (Notre Dame) and Tom Osborne (Nebraska).
Osborne quit coaching at age 60 with his teams having registered a record of 60-3 with 3 national championships over the last 5 years of his tenure. That's what you call getting out at the top. Few guys have the wisdom to do it.
