The Vision of the Anointed, Self-Congratulation as a Basis for Social Policy, by Thomas Sowell (isbn 0-465-08995-x)This and A Conflict of Visions are probably the best two books on conservative thought published in the last ten years, IMHO.
The New Science of Politics by Eric Voegelin (ISBN 0-226-86114-7)Now I don't think that Eric V is one to be taken up for light reading. It is like a strong sauce that has been cooked to a heavy reduction. But this was my first exposure to E. V. whom Russell Kirk liked to cite.
And, of course, I can't add Eric without pinging his biggest proponent, betty boop. Now, betty, I hope you have some time to add a list every once in a while. With you, I am going to have to add that you need to add an asterisk to those that we mere mortals can read without our unabridged dictionary, LOL.