I've read four of them now, and I think they get better with each book. There are some Mary Sue-ish elements, as one of the commenters on my original post pointed out, but Sookie becomes more fleshed out and more real with each book. And she's genuinely clever, making the books often quite funny. The mysteries are quite good, the new characters she introduces in the later books interesting and well described, and I like that the books are different enough that having seen the show doesn't mean I know what's going to happen.
Oh, one funny thing. In the fourth one:
things change for Sookie and Eric, who have a kind of edgy relationship. Eric suddenly has amnesia, inflicted by one of the bad guys. And, in his amnesiac state, he's much more open to being close to people and they develop a much more loving relationship. When he gets his memory back she remarks to herself that she liked him better with amnesia.
Well, all that happened to Scott and Logan in my series We're Not What You Think, right down to Scott thinking that he liked him better with amnesia. And I wrote it first!
Okay, so my fiction predicted - in 2004 - Barack Obama becoming president in 2008, and now this. You heard it here first.