^ is correct... Both are brilliant, but they do very different things.
The Manchurian Approach, along with Reality is Plastic by the same author, is popularly considered amongst if not the best starting place for beginner hypnotists. If that's your thing, you can't go wrong.
ParaLies is another excellent book, but is dedicated more to mainstream mentalism. The material is simply different. To give you an idea, the effects are largely pseudo-suggestive, using non-suggestion techniques to create the illusion of suggestion. There are some new takes on old effects, an excellent discourse on equivoque, and some surprising new concepts and routines as well. It also contains Thought Chunnel, which is worth several times the price of the book (I know that this is often used in marketing... In this case, it's true).
So which should you get first... Basically, whatever interests you more. Do you want to perform mentalism first, or do you want to learn hypnosis first? Both products are fantastic value and I'm sure you'll enjoy them both.
Let me (or D ICE R) know if you need more help