THe main reason that people dislike the movie is that they are not familiar with D&D. It's confusing and silly to those who don't know about the D&D themes. If you play AD&D, or PC games like Baldur's Gate, Planescape:Torment and even the classic Eye of the Beholder games, or read the novels (Forgotten Realms, Dragonlance are the two best), then you will likely find it enjoyable. Non-D&D fans, don't bother unless you like Fantasy movies.

FH_Mephisto - "I am all that you have grown to fear." Fear controls you. It is all around you. You can run, but you can't hide, as fear is everywhere. The bravest of souls have stood up to it in history's wake, but succumbed to it's icy embrace in the end. Soon, you too, will succumb.