Some of my friends saw "Cursed", and hated it so much that I ended up wanting to watch it. Truth to be told, I didn't hate it, and I even had fun sometimes. This may seem strange but... at times this movie is so bad that it is actually good.
The plot isn't terribly realistic, as the story is about Ellie (Christina Ricci) and her young brother (Jesse Eisenberg), both bitten by a werewolf. One is in denial, the other isn't, and the most extraordinary things happen to them as they get to terms with the curse of the werewolf. Add to that Ellie's mysterious boyfriend (Joshua Jackson), a werewolf on the loose, a few murders, somewhat exaggerated special effects, and you have the recipe for "Cursed".
The major flaw in this movie is probably the ending, but I think that you can live with that if you just want to see an uncomplicated movie that keeps you entertained. Don't take "Cursed" seriously, and enjoy it. If you think you can do that, and you like horror/paranormal movies with some comic elements, then this is likely to be a good movie for you.