Quick, give me your thoughts on the episode where Superman is flung into the future and grows a beard. And your thoughts on "For The Man Who Has Everything".
If you haven't seen it, I would recommend Batman Beyond because it's awesome. I'm very partial to that Batman suit.
As for Hal vs John, I first heard of Green Lantern through Justice League so...John. Hal seems like the kind of guy you see in a bunch of comic books while John, even if he's a little bland, feels a little more unique to me. To be honest, I don't know much of anything about the Green Lanterns. I just know they made for rad episodes in the JL cartoons and the movie First Flight was pretty dope at the time I saw it.
I should've watched Bruce Timm's GL series when it aired. I heard noting but good things about it.