Eric Mangini was the best by far but he was seemingly blackballed out of coaching after his stint with the Browns. He was the head coach who gave Peyton Hillis his chance while also playing four and five White starters on defense. They weren't that successful, after all these are the Browns we're talking about, but were on their way in 2010 as they finished that season very strong only to have veteran Castetard Mike Holmgren fire Mangini after the season and begin a completely unnecessary "rebuild." That was the last time Mangini was an NFL head coach.
I had to check but Mangini was the Jets head coach for 3 years before his 2 year stint with Cleveland. Funny that the Jets fired him after a 9-7 season and 2 winning years out of 3. For a loser organization this is great results.
Then as you said, barely anyone wins in Cleveland and his record there is admittedly bad. Seems his last season was up and down. The team had a huge upset against the juggernaut Patriots in NE, where Peyton Hillis ran for 184 yards and 2 TDs. The Browns ended the year with a 4 game losing streak, likely dooming Mangini.
Sadly, since then his last gig was 49ers defensive coordinator for one year in 2015. I’d say he deserves another shot, and he’s only 52 years old. However he’s not even coaching anywhere at the moment so there would be many hurdles to make this a nearly impossible task.
