I can't believe no Bears fans have mentioned Coach Halas, 6-time NFL champion,the first coach to treat coaching like it was important -- first to hold daily practice, first to use film. First to use the T-formation (first formation in which the ball was snapped to a quarterback), First to send men in motion.
In 40 years as coach of the Bears he had only 6 losing seasons and if I'm not mistaken, only Don Shula's won more games.
He was among the 11 coaches who started the NFL for christ's sake. While I've gotta respect Landry's effect on the game, it doesn't touch Papa Bear.