I actually liked the Green Lantern movie: it's not as bad as others make it out to be.
The same can be said for the new animated Green Lantern series on Cartoon Network - it's not perfect, not by a long shot....but it's actually pretty good, especially if you're willing to be open and actually commend DC for taking some interesting creative chances.
First, let's get the negatives out of the way - this initial foray into CG for DC animated looks...a little unfinished. It would be easy to make a cheap crack like, "Bruce Timm in CGI eerily resembles The Incredibles" - truth be told, it's a little too clean and unrefined for my tastes, but once you get past that...."Beware My Power" (the initial two-part opener) really sets the stage for what promises to be a halfway decent space opera/science fiction/super hero hybrid.
However, Frontier Lanterns (which sounds like the title for a great spin-off series) are being systematically slaughtered by the Red Lantern Corps (an obvious nod to Geoff Johns' work, as well as seemingly setting up the major arc of the series). Thankfully, there are no super-obvious riffs on potential "adaptations" of past Lantern stories, and it's a pretty decent animated take on the Lantern.
First episodes, by their very nature, aren't perfect - they're meant to introduce, provide the context, and then set the tone. Cartoon Network's animated Green Lantern isn't perfect, by a long shot....but it's well worth your time.
Now, when's the second season of Young Justice?