16. Gregg Williams
Williams brought as much joy to Bills fans as Krampus does to naughty children. The Bills Mafia must have wondered what they did wrong to have to suffer through his time as head coach. A renowned defensive coordinator, Williams is also notorious for running aggressive plays.
His time in Buffalo saw him post records of 3–13, 8–8, and 6–10. How on Earth did he manage to see out his full contract? Obviously, their ownership just didn’t really care that much because he overstayed his welcome. But they didn’t renew it and Bills fans could finally breathe. The current Jets’ defense coach is also infamous for his role in the New Orleans Saints bounty scandal.