So from that perspective - here's some thoughts on the Watchmen movie. Be aware that this entry possibly contains spoilers.
So... I've been waiting for and fearing the appearance of this movie for quite some time. And as a fan of the comic, it's a very satisfying experience. Many shots are taken directly from the comic (I'd like to watch it with comic in hand, actually, just to see how many times it matches up like this). Several things have been eliminated, most notably Ozymandias's grand effort to create a giant squid from outer space that will broadcast psychically when it dies, and the various clues, such as the missing scientists, that point towards this. Instead, he is framing Dr. Manhattan. It works okay, and it keeps the movie from being four hours long instead of three.
Also eliminated are some of the small human lives seen in the comic book: the taxi driver and her girlfriend, the boy at the newstand, the dinner party with the prison psychologist. That removes some of the impact of Ozymandias's act, but okay, length issues again.
I'm getting a little tired of stop/slow motion flashes in fighting scenes, but maybe it's just me. Also not really keen on some of the more stylized fighting moves because they seem...silly.
Some of the actors are TERRIFIC, most notably Rorshach. The woman who plays Laurie/Silk Spectre II was not one of them, but a hot lady kicking ass in spandex compensates for that somewhat.
So I liked it, overall, but it seems to me a lot of the graphic novel's soul has been surgically removed. Part of this may be that terms like "Who watches the Watchmen?" have taken on a new resonance in the past decade, and Snyder neatly sidesteps this by making it clear that the movie is not set in the current day but nearly three decades ago. (Cripes, that makes me feel so old.) The moment with Laurie and Jon on Mars when he speaks of the complexities that have produced her has little impact (partially because much of the stuff pointing towards her parentage has been obscured, so the significance is lot) is her, and yet it's one of the most meaningful in the graphic novel. Similarly, Bubastis appears as a prop in a final scene, rather than having been around throughout the long, and so the moment of her death and Ozymandias's willingness to sacrifice her is underplayed.
We also lose the knowledge that Ozymandias has been manipulating people through advertising and merchandising all along. We see glimpses of it, such as the commercial the Comedian is watching in the beginning, but it's not made clear. That's a little frustrating, because one of the points about Ozymandias (or so it seems to me) is that he is a creature of knowledge. It's his intelligence that makes him such a good fighter, not fast reflexes, and that plays into some of the novel's message.