Yeah, I like your top 4. And I don't dislike including LT, but just feel like there is someone else that could be up there ahead of him. But still, can't really argue too much with any of those choices.
Not arguing with you, exactly, but that is the era in which I grew up. I don't think people quite realize how he changed the game. I can remember seeing the L.A. Kings (with Gretzky) play the Hartford Whalers (my team at the time) and being MESMERIZED by his play. He was literally playing a different game. At times (and it happened more than once) I would be watching - and be aware that I played competitive hockey into college, so I know the game at least more than as a beginner - and I'd be like "what the hell is he doing??"; he'd be off in the corner, or he'd be trailing the play and seemingly out of the mix, and seconds later he's standing there, 10 feet in front of Peter Sidorkiewicz with the puck, making him look silly (the Great One had a goal and three assists, for a team that was mired in a slump at the time). It was hockey at a totally different level.
LT was the same way. Even Belichick has said he's the greatest player he's ever coached (though also "greatest DEFENSIVE player he's ever coached", and "the greatest defensive player in history"). Think about that for a second. Bill Walsh - no slouch as a coach - devised an entirely new offensive set (basically a two-tight end set) to block him, because the old way - picking up a linebacker with a running back - was laughably ineffective.
Parcells even changed his coaching style for him. It's legend that Parcells rode Phil Simms as hard as he could to get him to excel - to the point that Simms hated him and considered quitting football - whereas he let LT have a loose leash (allegedly doing coke and cavorting with hookers, even on nights before games).
LT belongs in that top five, for sure.