I've read the first and the second books and I also prefer the tv series. I liked the second book more but that may have to do with the fact that it's totally different from the series. The story of the first book seemed to me very poor in comparison with the way it was told on the series. I didn't really get the ending of the first book, it seemed rushed and incomplete. As for the ending of the second book, I loved it. I found it was just perfect the way Dexter's problem Spoiler (sargent Doakes) is taken care of without his direct involvment (and therefore, without breaking Harry's code).