Top 20 Coaches in NFL History (IMHO):
1. Paul Brown - His teams won seven championships. Was one of the greatest innovators that the game has seen, including popularizing the teaching aspect of the game and setting the early parameters for scouting. Developed great coaches as well, such as Shula, Ewbank and Walsh.
2. Vince Lombardi - The first known "motivator coach". Made up for lack of innovation with the ability to reach his players. Never had a losing season in his career, and won five championships.
3. Don Shula - The all-time leader in wins, and a success in multiple stops. Won with both conservative attacks as well as a wide open passing offense. Won two championships. Would rank higher on the list but for key losses in big games (1964 NFL Championship, Super Bowl III) and the fact that he did not win big without Bill Arnsparger.
4. Tom Landry - Rates alongside Brown as one of the great innovators in NFL history. Invented the multiple offense and popularized the 4-3 defense. Revolutionized the game with his method of using keys to predict tendencies. Was his own offensive and defensive coordinator. Won two championships, but had a shot at winning many more. His many losses in championship games keep him from being higher on the list.
5. Chuck Noll - A coach who gave his assistants and players much more freedom than the others above him on this list. Championship teams built on defense, which reflects his background. Won four championships, and lost three conference title games. Would rate higher if he had success in a decade other than the 1970's.
6. Bill Walsh - Developed the precision-matchup offense, better known as the West Coast Offense. An underrated motivator, he learned at the feet of two greats in Brown and Sid Gillman. Won three championships, but had a hand in building the 1989 49er title team. Did not have the longevity of some of the coaches above him, mostly due to getting a late start as a head coach (he was 48 when he became a head coach for the 49ers).
7. Bill Belichick - A defensive mastermind, he overcame a poor stint in Cleveland to redefine himself in New England. Has won three championships, and had a strong hand in two championships as an assistant. Sound philosophy who has contributed more to offensive scheming in New England than widely known. Spygate and his Cleveland tenure keep him further down on the list than many would rank him.
8. George Halas - The founder. The history of the game would begin with his name. Largely responsible for building and keeping the game alive during some tenuous times. Developed methods for practice and film study that ushered in offensive growth in the game. A gritty, no nonsense coach whose teams won six championships. Would rank higher if not for a huge gap with little success between 1946 and 1963.
9. Joe Gibbs - Developed a revolutionary one back offense with a flex TE that is still used today. Learned at the feet of Don Coryell. Won three championships with three different quarterbacks. Would rank higher, but two of the championships took place during strike shortened seasons, and his comeback stint was mediocre.
10. Hank Stram - Another innovator as a head coach, developing the odd man front on defense. Like Landry, coached his own offense and defense. Won three AFL championships and one Super Bowl.
11. Bill Parcells - Perhaps only surpassed by Lombardi as a motivator, Parcells won two championships, and led three other teams to the playoffs. Would rank higher but for, similar to Shula, a lack of championship success without Bill Belichick.
12. Weeb Ewbank - Ewbank won three championships as a head coach, and developed two Hall of Fame QBs in Unitas and Namath. Ewbank won arguably the two most important games in NFL History (1958 NFL Championship and Super Bowl III). A master strategist on offense.
13. Jimmy Johnson - Johnson did what seemed to be the impossible, taking the Cowboys back from 1-15 to a Super Bowl title within four years. Built one of the most talented, deepest teams in NFL History. Won two championships, and built the team that won a title in 1995. Would rank higher if not for a lackluster stint with the Dolphins, and a 62-7 career finale.
14. Sid Gillman - The father of the modern passing game, having passed his theory along to many coaches, such as Walsh, Al Davis and Don Coryell. His numbering scheme for passing routes is still used today. Won one championship.
15. Curly Lambeau - The founder of the Green Bay Packers, similar to Halas, the history of the game would begin with him. Won six championships as a coach, and was the all-time winningest coach for many years. The end of his Packer tenure, as well as flameouts with the Chicago Cardinals and Washington Commanders prevent him from being higher on this list.
16. Steve Owen - The first great coach of the New York Giants, Owen was a defensive genius, developing the umbrella defense, the forerunner to the zone defense. Helped develop Tom Landry's coaching skills. Won two championships with the Giants.
17. Dan Reeves - A stalwart as an assistant coach, Reeves had a hand in two championship teams, and led three teams to the playoffs. He also led two different teams to the Super Bowl, but did not win in five tries. Never had the best team on the field in any of those games, but he always got the maximum amount from his talent.
18. John Madden - His television work obscures his coaching success, but make no mistake about it, he was a terrific coach. Won 100 games earlier in his coaching career than any coach who preceded him. Won one championship, and would rank higher if not for an inability to beat the Steelers in big games (the one time that he did, he won the Super Bowl).
19. George Allen - A master in strategy, deception and motivation, Allen was an outstanding defensive coach who got a late start as a head coach (48 when he became coach of the Rams). Largely responsible for the Bears 1963 championship, he took two teams to the playoffs, and went to one Super Bowl without winning. Was the first to make Special Teams a coordinator level position.
20. Bud Grant - Grant did win three championships, but those wins were in the CFL. Grant led the Vikings to four Super Bowls, but his teams were overpowered each time. Had the misfortune of coaching in an era where Shula, Noll, Madden and Landry had dominant teams.