I'd give him a rock solid B. DC has their big 3 and GL has never really cracked or added to it. In comics, he's a star, but I think if you look beyond that, which you have to if you're talking A list, he's had a hard time transcending the medium from which he came (example: his movie). Batman, Hulk, Superman ect have had tv shows and movies over the years and are the kinds of characters that have proven appeal to the masses. I'm not ruling out that GL can't become A list in the future, like Iron Man seems to have, but right now I'd have pretty poor results asking the average simpleton Green Lantern's identity and powers.