What's the purpose of your question, Liosse?
If you want a source for good books to read, then we must recommend those blogs that have helped us find great books. But if you want to know where you should send your own books for reviews, to attract readers, then the question is which blogs have the greatest reach, or even, which have the best conversion rates (of sending readers off to Amazon et al.).
The answers to those two questions might differ.