I'd go with Gibbs, Baugh, Green, and Sean Taylor.
Gibbs - duh
Baugh - I read an article on him a couple years ago that really put his greatness in perspective for the era he played in. It's not
this one but this was the closest I could find to it. He was putting up numbers back then that would be impressive today. Overall, he's probably the best player ever in Redskins history.
Green - I only got to see his last couple of seasons, and back then I didn't even understand football that well. But the longevity and the standard he set every year will be hard to duplicate.
Sean Taylor - I had to include somebody from my generation, and he's the obvious pick. 2006 notwithstanding (which was a bad year for the defense in general) 04, 05, and his legit All-Pro half a season in 2007 (which I think probably stood our best chance at securing a first team All-Pro in the last 20 years) he was the best player on our team. His physical attributes were off the charts, and in 2007 when it all clicked mentally I firmly believed we were witnessing his ascension in the Reeds/Polamalu's of the time. Watch Greg Williams marvel at his 2 pick game against Brett Favre (one of which he had to cover so much ground nobody even thought it would be a pick), hell, go back to his rookie season denying Randy Moss on a deep jump ball (how many guys could do that?) and tell me I'm crazy. My favorite player to ever put on a Redskins uni, and he definitely deserves a spot on my Redskins Mt. Rushmore.