I love book reviews that mention other books. Comparing and contrasting books, especially popular titles where even if you haven't read them you know the general idea behind them, is a easy and quick way to know if I'm possibly interested in reading the new title. One of my favorite websites to read book reviews is Goodreads. You can post your progress on the books you're reading, read your friends reviews (if you're linked through Facebook), and even get status updates from authors on their latest works.
If the review compares the books to books I haven't liked in the past, then I usually won't bother reading it. But every once in awhile, there's a review that compares a book to more than one of my favorites and then I try to get my hands on that title as soon as possible. That's how I ended up reading Divergent, which I ended up liking more than The Hunger Games.
A recent example of this is when I was reading reviews of popular new releases, and I came across the book The Museum of Extraordinary Things by Alice Hoffman. I'm not going to quote the review, because it would give away major spoilers (Thanks reviewer!) but it compared it to the Night Circus and Water for Elephants. Since I enjoyed both of these books, I'm hopeful that I'll enjoy Hoffman's new book which I'm now officially putting on my bucket list.