It really comes down to what your own requirements are, and the way you're presenting it.
Derren Brown did a book test as if he'd memorized an entire (fairly large) book in 20 minutes (I believe). That allows him some leeway in presentations that a psychic presentation wouldn't allow.
Personally, if I'm going to do a book test I want it to be very clean. I want the volunteer to be able to pick up the book, open wherever they like, and read silently, and I start to tell them what they are reading. Mind you, I would use another method that isn't my preference if it suited the show better.
No forces, no fishing, no anagrams. There's a series called Doppelgangers that allows this, and that is the only book test I really like and would feel satisfied using, I think. The downsides are that they are expensive, often difficult to purchase unless you know when they are being released (usually sell out fairly quickly), and there is some memory work involved. But aside from those aspects, it's the most clean and flexible book test I know of - the volunteer opens the book anywhere and reads silently, and you start to tell them what they are reading - and they can flip back and forth and you can continue telling them what they are reading.
Another good option is The Brook Test by Paul Brooks. You can use any book with minor preparation and it's pretty clean from there. But it's a single word reveal.
So what kind of book test are you looking for? What experience are you hoping the audience has?