While it can be hit or miss the website www.whatshouldireadnext.com is also a good place to start if you are looking for a book.
I will say that when the site misses it is off by miles. But nothing is perfect.
Here is the homepage blurb about the site:
Enter a book you like and the site will analyse our database of real readers'
favourite books (over 65,000 and growing) to suggest what you could read next.
(You can register on the results page and build your own favourites list)