I just got back from Green Lantern...here are my thoughts (spoilers):
I think this movie is getting too much hate to an extent, but the story is VERY flawed. This is a 2 star script somewhat saved by visual aspects. The characters are very shallow. Hal is the only character with really any depth. Tim Robbins was useless. Hector Hammond was whiny and useless, though he had potential to serve as an effective mirror for Hal. But, in the end, Hammond is tossed aside like a punk and we get no payoff. The mirror aspect is shallow. Blake Lively does very little but bat her eyes and pine for Hal. She was useless. Parallax was defeated far too easily for my taste and I didn't like the design. Killowog does nothing. Tomar Rae does nothing but narrate. Sinestro was well acted, but he had no arc. He sees the power of fear, but the power of fear was defeated by a single Lantern. He showed respect for Hal and seemed to realize how right he was in fighting fear. Then, he takes the yellow ring anyway? Makes no sense.
The visuals were good enough to elevate the film a bit over the script. But, the story had many problems.
3/5 based on enjoyment...but rating it objectively, prob a 2/5