Critical Thinking discussion

What is the best book you read on critical thinking and why?

please recommend a good critical thinking book

Besides my own (Logically Fallacious), I enjoyed Guy Harrison's "Think." Easy to read, enjoyable, and contains a great overview of many of the element of CT.

Bo wrote: "Besides my own (Logically Fallacious), I enjoyed Guy Harrison's "Think." Easy to read, enjoyable, and contains a great overview of many of the element of CT."
thanks for the recommendation!