I found the book made me uncomfortable, in sort of the same way I feel when I'm watching a masterfully-made infomercial. This, to me, is a sign that it was working. ;) If the sport of negotiating was as natural as breathing for me I wouldn't be reading a book about it!
Winning Through Intimidation was a fun read, especially if you're into real estate. Apparently the book is worth a lot now (I had no idea, I have an old hardcover version that I don't even see here)
I was reading "Bargaining for Advantage" this weekend after reading another recent salary post and also recently re-negotiating my salary. I really like the book because it kind of sets down a clear set of steps and vocabulary to refer to them, and because it emphasizes information and assessment of the situation rather than psychology.