Liberal Fascism by Jonah Goldberg. Go buy it right now and read it. Now. Go. Hurry up.
Seriously though, this is a fascinating book that basically centers on what fascism really is and how, in today's society, our ideas of it and our understanding of "right" and "left" when concerning politics is, essentially, a bit skewed (and not all that accurate).
Filled with page after page of "whoa, I didn't know that" and "I never thought of it that way" type stuff, the book is incredibly well researched and worth every minute of your time if you are at all interested in the nature of politics today and the history behind it. I can't recommend it highly enough for someone interested in history and/or current affairs.
I won't bother with the details (read the description at the link provided) unless the debate happens to kick up in the comment section (from any one of the four of you who still read this blog).
Update: The blog for the book and answers to some criticism of it can be found here.