Jim Cameron has taken up a few hundred notches with Avatar. Simply amazing. Great storytelling and character development with incredible special effects that totally immerse you into the world of the Na'vi. Do not miss out on this amazing experience, it's worth every penny of a $15 Imax ticket.
Having read the graphic novel before watching Watchmen, I was satisfied with the movie. Granted there were some very cheesy and unnecessary moments and elements (i.e. sex scene in the Archie mobile, unnecessary inclusion of Manhattan's blue wiener, ridiculous looking Bubastis etc.), the film as a whole was entertaining.
If you read the graphic novel beforehand, you'll appreciate more the scene selections and story progression. Otherwise, like most people I saw in the theater, you'll probably doze off on some scenes. There are plenty of spots where the film could have been improved to get the audience more interested in the characters. Also, the musical choices were ill-fitting and oft-times cheesy.