The best coach in the NFL is Bill Belichick. In 12 years as New England's head coach he has lead the Patriots to 5 Super Bowls. Since he became the head coach the Patriots have only had one losing season which was in 2000 when the Patriots went 5-11. He makes good decisions when the game is on the line. He has a great relationship with his players and is loved by the Patriots organization.
With New England his coaching record is 151-57 which is a great record. If his team gets blown out he makes them work extra hard at practice next week to fix the mistakes they made in that game. He has signed good players that are available such as Wes Welker and Tim Tebow. He never makes excuses for his teams play. He has had a great coaching career and will win many more games in the coming years.