My Chess Books Vol - 10: Karpov's Collected Games 1961-1974
I got this book for $15.00 used. Seems steep but I got it not just for the 530 collected games. There is great analysis, as well as some good background on Karpov. The secondary reason for getting this book was the manner in which the games are presented. Levy gives you the openings and more, also my copy came with lots of analysis and notes by the previous owner... and lots of it come with explanations. I definitely recommend this book, and if you can try finding a copy that has some ideas added by the previous owner, I almost always find that helpful.