When I was young I used to read Superman, Batman and all the others, back when the only place to get US comics was on Blackpool shore. Back in the late 80s and early 90s however US comics started appearing in newsagents like the one in Monifieth. I picked up two of my favourite DC comic titles - Aquaman and Green Lantern: Emerald Dawn.
Hal Jordan, US (naturally) test pilot is selected by the Guardians of the Universe to join the Green Latern Corp, an army of intergalactic space corps armed with green rings that allow them to build any construct or do practically anything their imagination can conceive of.
Eventually other Earth Green Lanterns were chosen, including John Stewart, in a 70s socially minded revamp. Eventually Hal turned evil, laid waste to the Green Lanterns and a young fella called Kyle was chosen. Hal's better now, and Green Lantern again, but only John and Kyle have appeared in the ace Animated DC Universe.
I said I thought John Stewart in the Justice League cartoon which I started watching was pretty dull. This clip proves I'm wrong, everything after 3 minutes in this video is pure cinematic genius:-
A suspiciously Hal Jordanesque origin is also on YouTube (not sure how legal that is, but the entirety of the John Stewart one is there if you look.