YARRRRRRRRRRRRRRRR

So yesterday, I finished watching all of Justice League and Justice League: Unlimited.

Green Lantern is one that I really don't know much about, aside from Flash. So I basically am relying on:
-what people have told me about them
-What I've seen on the show, or a few crossover comics.

Okay, so the power of the ring is from Willpower and limited only by the wearer's imagination, right?
So does John Stewart have the least creative imagination ever or something? Or was this a limitation of the show/budget of cartoon itself?

Because honestly, aside from the episode "Kid Stuff" when he's 8, his ring makes only shields, fists, and shovels.
WTF John.

Also, for anyone who curious about reading Green Lantern comics, what do you feel would be a good starting point? Which GL character?

Did you like Justice League?

Tangent: What would be a good intro for Flash? Which Flash do you like? Or do you hate Flash? Will I stop asking questions?