"A film is--or should be--more like music than fiction. It should be a progression of moods and feelings. The theme, what's behind the emotion, the meaning, all that comes later." - Stanley Kubrick
"I don't take movies seriously, and anyone who does is in for a headache." - Bette Davis
"You're only as good as your last picture." - Marie Dressler
I think there's a difference between types of good and bad movies. One is whether it is well-written, acted, directed, etc., and the other is enjoyment. Sure, they're contributory to one another, but one doesn't entirely change the other. For example, Pirates of the Caribbean: On Stranger Tides had a few plot holes (and I'd have to give it a C rather than my earlier B), yet it still was funny and exciting. Same with the newer Star Wars films, Eragon (the movie), Van Helsing, and the Inheritance books as well (which include Eragon and don't have bad plots, just somewhat unoriginal ones). There is a book I had to read for school called Anthem (by Ayn Rand) that was terribly lazy in its plot, had ridiculously blown-out ideas, and took itself way too seriously. Not something I'd read for pleasure, yet it somehow stood the test of time and is for some reason hailed as a "philosophical" classic.
Sometimes what we watch for fun isn't award material, but still fun. Also I wanted to mention that a movie based on a book can be unfaithful and still good, if done well in its own right (such as several Dracula films, Stardust, Willy Wonka and the Chocolate Factory [the old one], Frankenstein , etc.) I haven't read The Lovely Bones, but I enjoyed the adaptation. Stanley Kubrick's version of Stephen King's contemporary horror classic The Shining is disliked by many who have read the novel, yet I and many others love it (funnily enough, despite my being a King fan, I haven't read the book). I've heard similar things about Secret Window, another Stephen-King-based movie derived from "Secret Window, Secret Garden" - a novella featured in his collection Four Past Midnight. But Johnny Depp is in it and he's great. Plus I recall the writing and directing being interesting. But who knows? It has been a while.
James Cameron's Avatar is often accused of relying on special effects to tell a story. I disagree. While the story may not have been the most spectacular tale ever spun, there was not much wrong with it. I would say that there are two directors who do use effects to tell a story: Michael Bay (Transformers 1, 2, and 3 - please don't make a 4) and Roland Emmerich (2012, Independence Day, The Day After Tomorrow). At least Mr. Emmerich does not include as much sexism and racism as Mr. Bay. I think. I don't actually recall, but I won't willingly watch them again, although the effects in 2012 were at least entertaining.
But some movies are just torture to watch, like reading a phone book or tax records in place of a novel. These include Michael Bay films, any parody along the lines of Epic Movie (though I saw part of one Scary Movie installment, and it seemed OK), Son of Godzilla, Land of the Lost (Will Ferrell one), and anything by Tyler Perry. The reason I dislike Perry's movies is that they seem to all resolve in luck, meaning something JUST HAPPENS to go perfectly out of the protagonist's control, like a rich relative he or she didn't know about dying (Meet the Browns, which I was forced to watch once). And the humor is repetitive.
But don't worry, I do like plenty of movies. Just pointing out the not-enjoyable ones for me. I also have to wonder at people who base their opinions off of those of critics, such as my maternal grandmother. Many people I know didn't like the new Clash of the Titans, whereas I thought it was better than the original - a rare case with me. Maybe I missed something.
The point is, people should be free-thinking on media, not love everything but not hate everything either (like someone I know does [the latter]), and take in multiple factors. Don't ruin a movie for yourself because of a couple plot holes. And at the same time, look out for them! And don't love a movie because it's critically good but not enjoyable.
To quote a movie I don't remember the goodness of, but remember loving the book it was based on:
"Yes! That is all!" (Iorek Byrnison (voiced by Ian McKellen [also Gandalf], The Golden Compass, 2007 - based on the novel by Philip Pullman)