Two weeks ago I mentioned that I had just finished reading The Girl with the Dragon Tattoo and LOVED it. Perhaps my strongest compliment could be that the day I finished it, I started the second book in the series, "The Girl Who Played With Fire".
I loved it.
Loved, loved, loved.
The characters were well developed and interesting, with enough unique details that you could (mostly) keep them straight, the plot was detailed enough that you could follow, and the ending was surprising enough that you'd never guess it (although simple enough that once you read it, you're shocked that you hadn't guessed).
I am hooked on Lizbeth Salander. HOOKED.
Before I endorse the series too heartily, though, I should mention that the book (the whole series, in fact) is violent and graphic and not for kids. The material is dark, but the writing is superb and I will say that the book would not be as addictive or captivating without it. I do not like gratuitous or graphic violence in books or movies, and even I can understand why it was probably necessary to include in the series.
Again, the book is fiction, so I don't want to spoil anything, but I would highly recommend the series and I will begin the third book as soon as I can get my hands on it.