One of Eisner’s claims to fame was his splashes for the Spirit. A number of them are here at the link.
But this one, besides being famous, not only has a great image, but historic copy too.
Go look at a master at work.
And Darwyn Cooke picks eight allegedly great Spirit stories here.
And the importance of Eisner partly explained here. (To me, though, the most important thing is that he controlled his creations. A simple lesson still not really learned by creatives: Don’t give the copyright.)
To say that Will Eisner’s retention of his creator rights is the most important thing about him is to value his business acumen over his artistic genius. He was one of the half-dozen most important comic creators in the history of the medium.