I would give this book 2.5 stars if I could-- it's just not good enough for 3. I am mystified why it has received the acclaim it has. I have read many mysteries and thrillers that were far superior.
That being said, the beginning is interesting. I like the way the characters are introduced but once it gets into the Vanger family history it becomes boring beyond belief. I plodded away at finishing it because I had chosen it for book club. (Sorry friends.) If I had know what I was getting into, I would have passed on it. The violence is unnecessarily graphic and off putting. I also didn't care for many of the characters including the bland Mikael. I did like Henrik but that was it except for Salanger, my favorite character, who was interesting and complicated. She reminded me somewhat of Carol O'Connell's Mallory -- Stone Angel being an excellent book.
If I could do it again, for book club I would have chosen Dark Places by Gillian Flynn which is superior in all ways and has one of the most unusual and unforgettable female characters of all time. Really, don't fall for the hype surrounding this book. Save yourself some time and pass on it.
new note (April 2013): it's fun to see the acclaim Dark Places is finally getting!!!