The hp movies are so diffrent from the books especially the 4.

I watched the movies of both series before reading the books and I believe that the Twilight movies stick to the books more.

HP is very different, as zanhar said, and they leave out a lot of crucial info. My dad's never read either, but he grasps Twilight a lot easier than HP, since Twilight follows the books better.

They also added alot

Well I know that all of my friends but about three watched the HP movies without the books, and they loved them all. Now they're reading the books simply for the fun of it, so that's what I've based my pick on.
But I suppose that at the end of the day, it depends on the personal taste of the person watching and things like that :) x

They haven't cut out anything too important yet

HP is way too different.

They say TwiMovies are better than the books, and I say HPBooks are better than the HPMovies.

and with David Yates in charge? No, sir.

Twilight movies stuck to the book (Kristen said SMeyer is very stern about that) which is a good thing.

Harry Potter films after the second, pretty much assume you've read the books. That is why they don't bother with eliminating plotholes and the like. Moviegoers are just supposed to ignore the fact that most of the films make little coherent sense without the foreknowledge of the novels. Twilight, on the other hand, is just plain hilarious, no matter if you've read them or not.