First of all, I just want to offer a huge THANK YOU to Knok for putting this comprehensive list (with links) all together in one place for other TOEFL students. I'm sure that took a considerable amount of time, and it represents a very kind and selfless gesture. I just want to add a few comments about some of the books and links offered above to avoid any unwelcome surprises later...
1) As many know (inlcuding Knok), I strongly favor the "Complete Guide" book by Bruce Rogers when it comes to TOEFL preparation (for several reasons that were covered in another thread). HOWEVER, be careful when ordering this book. If you order it from amazon or several other merchants online, they may be selling just the book plus the CD ROM (and not the 13 audio CDs and answer book with audio scripts, which are obviously a critical component to your study plan). If the price is about $50 - $55 (USD), then I would be almost certain that you WON'T be receiving the audio CDs from that site. Here are 2 separate ISBN #'s that would include all the materials (the 800-page book, CD ROM, 13 audio CDs, and answer book): 1-4240-9939-9 and 1-4240-9937-4 (it's called the "International Edition," but it comes with the EXACT same components).
2) While the "Official Guide" put out by ETS through McGraw-Hill is technically as accurate and realistic in its practice material as the Thomson-Heinle (as it should be, since THEY are the ones making the test), you need to know that even in the new and improved 3rd edition there is a grand total of just TWO practice tests. Therefore, if you are a student who is striving to reach a 26 in speaking or 25 or higher in writing and want several examples of speaking task #5, for example, or integrated writing passages to work with, please understand that through this book you will get just TWO opportunities to do so.
3) Delta's "Keys to the TOEFL" was one of the first books I used in the classroom back in 2005/2006 when this test was being introduced. I think it does an outstanding job in some areas, such as how it breaks down the independent writing. However, some of their integrated writing and speaking tasks are seriously flawed and quite different from the actual patterns on the ibt (such as task 5 with THREE suggestions instead of two, task 6 with four different sections to cover instead of two, lectures in the integrated writing that both agree AND disagree with the reading passages and where the key points between the two passages don't match up, etc., etc.).
I guess buying a TOEFL book is a bit like buying a car -- it really depends on your exact needs (for example, whether you are a first-time TOEFL test-taker looking for an overiew of the entire test OR a seasoned TOFL veteran who needs intense practice in just one area). In any event, best of luck to all of you. May you reach your TOEFL goal as soon as humanly possible!