Agreed. I did say arguably though...
Charles Woodson, Rod Woodson, Darelle Revis, Ed Reed, Ronnie Lott, Mike Haynes, Darrell Green, Deon Sanders, Richard Sherman, Champ Bailey, Lester Hayes, Rodney Harrison, Steve Atwater, Adrian Wilson ... Those are the names I most recall. Being in my late 40s, they span late 70s to current.
Remarkable story. Signed by Kansas City as an undrafted free agent punter in 1981, then cut in training camp. He was a great athlete who had played defensive back in college, so they brought him back later in the season when injuries left them shorthanded. He turned out to be arguably the best free safety of his era -- five-time All-Pro, NFL All-Decade team, and anchored the group that I always considered the best defensive backfield in the NFL those days, with cornerbacks Albert Lewis and Kevin Ross, and strong safety Lloyd Burruss.