Lisbeth is the movie - and I liked Rooney Mara's performance far more than Noomi Rapace. I think that Fincher went for a far more eerie 'ice' portrayal for Lisbeth, and Mara did a superb job with the creepy/vulnerable aspects of Lisbeth.
The graphic scenes aren't as graphic as you think they are in Fincher's film. They are more graphic than Oplev's take - but, there still is a lot that you just think you see.
Books are best - then I would go for Fincher take next. I was worried when I read there was to be an english speaking remake of Oplev's films - which I really enjoyed, but I really believe that Fincher got the layers of the characters put on the screen far better than Oplev. I also think that Fincher's editing is far superior, and the cinematography in Fincher's version - stunning - the TV look of Oplev's is very apparent once you watch Fincher's film.