{in no particular order}:
Jim Parker
John Hannah
Walter Jones
Jonathan Ogden
Rosey Brown
Cal Hubbard
Danny Fortmann
Bruce Matthews
Anthony Muñoz
Larry Allen
Randall McDaniel
Gene Upshaw
Art Shell
Forrest Gregg
Centers
Mel Hein
Jim Otto
Mike Webster
Dwight Stephenson
Thoughts? Comments?
One note on Anthony Muñoz: on the “response” show for OLs and TEs today (I’d recorded it) I heard a story from former S.I. writer Peter King from his days covering the Bengals that after one game an assistant coach for the Bengals told Peter King to “come in here, I wanna show you something.” Peter King obliged and the assistant coach told him: “this is the first time. The first time that I’ve ever given a perfect grade to an offensive lineman for his performance for a whole game” saying that in 64 snaps that day Anthony Muñoz didn’t make even one mistake. I think it was the first game of Anthony Muñoz’s second season (the clips they showed while Peter King was telling his little story suggested, to me, that that game may very well have been against the Seahawks). Also, from the same game that coach claimed that Anthony Muñoz pancaked his opponent on 26 separate occasions which, the coach said, he could guarantee Peter King - even though statistics were not kept on such things - that that had NEVER before happened in an N.F.L. game.
And a few notes on Dwight Stephenson: although I don’t really remember him I’ve heard and read raves about him. Such as a story about the time when the Dolphins were playing the Patriots and he, allegedly, tossed TWO Patriots defenders aside, on the very same play, as if they were children. Or Matt Millen claiming that “as good as Mike Webster was, and I played against Mike Webster”, “Mike Webster wasn’t even in the same orbit as Dwight Stephenson (as an N.F.L. center).” Or another story from Matt Millen about how the very first time the very capable veteran NT of the Buffalo Bills, Fred Smerlas, played against Dwight Stephenson he was manhandled. Or MY favorite: that in the midst of Anthony Muñoz going to all those Pro Bowls and being named first team All Pro several years running, Dwight Stephenson was named “Best lineman” in the N.F.L. several times by the NFL Alumni Association.
No Joe Thomas? That’s most definitely a glaring and horrid omission
I have Joe Thomas down as the Browns’ starting LT (ahead of H.o.F.er Lou Groza and Dick Schafrath) in my G.P.o.A.T. League, for what that’s worth. 
I was glad to see that Jim Parker was a unanimous choice. The man was unreal.
If you’re including him, then one needs to consider arguably the best unsung LT that’s currently active, Mr Andrew Whitworth, whom was every bit Joe Thomas’ equal.
I always felt Thomas was a little overrated but that’s likely a function of how terrible the teams were he played on.