The original Green Lantern, Alan Scott! With The Flash there were two of the major characters rebooted and redesigned by DC in the late 50's/early 60's, before joining the JL. I was familiar with the character again for the Superfriends show, but I hardly knew about the vast mithology developed in the last decades. I didn't hate the live-action movie, there are far worse examples in that area, but it just scratches the surfaces of such rich universe.... the basic concept to create anything and the color mithology is pretty interesting.
First Appearance: All-American Comics in 1940.
The original design mas pretty simple, a guy with colorful green pants, a big size red sweater and a dracula type cape.
(On a side note for some reason the ring switched sides from time to time in the covers...)