1. Marvin Lewis (2003-2018)
Following Dick LeBeau's disappointing coaching tenure, the Bengals were in search of their ninth head coach in franchise history. They landed on Marvis Lewis, who had served as Washington's assistant coach and defensive coordinator in the 2002 season.
Before he came to Cincinnati, Lewis had coached various different position groups for Idaho State, Long Beach State, New Mexico, and Pittsburgh before moving to the professional ranks. He served as the Pittsburgh Steelers' linebackers coach from 1992 to 1995 and then spent the 1996 to 2001 seasons as the Baltimore Ravens defensive coordinator.
Lewis had been behind some of the toughest defenses in the league around that time so it made sense when the Bengals brought him in. Little did fans know at that time that Lewis would be the leader of the Bengals for 16 years.
Lewis' Bengals teams started off decent, not posting a losing record in his first four years at the helm. He did have some lean years from 2007 to 2010 and while many other franchises probably would have parted ways with him during that time, the Bengals remained dedicated.
The dedication paid off with impressive seasons from 2012 to 2015 but unfortunately, it didn't translate to playoff victories. That's the knock on Lewis as a coach is that he was never able to lead his team to a playoff win.
Following a lackluster 6-10 season in 2018, Lewis and the Bengals mutually agreed to part ways. He finished his 16-year Cincinnati Bengals tenure with a record of 131-122.