Sherk, Shields, Igor, and Murilo mother fuckin Bustamante (my pick for most underrated fighter in history) are probably the top guys when one mentions underrated fighters.
To TS, Lytle was the man. He embodied what being a fighter was. Not an A level athlete, not some new breed shit talker, just a guy who went out to scrap and gave it his all each and every time out. The guy was a warrior through and through and I have nothing but respect for the man.
Sherk, Vovchanchyn, and Bustamante all received a lot of credit during their primes. Shields did not. This, I think, separates him from the rest. Maybe history has (unfairly) forgotten the other 3, but Shields NEVER got his due. And he deserved it. Still does.