8. Chan Gailey (2010-2012)
Record: 16-32
In 2010, the Buffalo Bills were right in the middle of their playoff drought and elected to go with a coach with head coaching experience when they hired Chan Gailey. He was the Cowboys head coach in 1998 and 1999 and after two seasons with the Miami Dolphins offensive coordinator, he would coach in college as the Georgia Tech head coach for six seasons from 2002 to 2007.
Chan Gailey was an offensive minded coach but he wasn't really able to get the offense going as the Bills never finished better than 14th in his three years with the team. The best season for Gailey was in 2011 as the Bills got off to a 5-2 start that also included a win over the New England Patriots.
It looked like they might be on their way to ending the playoff drought however, they struggled down the stretch losing eight of their final nine games. The Buffalo Bills probably should have made a switch after the season but brought Gailey back for one more year and after going 6-10 he was relieved of his duties as head coach.