Greene, Robert; The 48 Laws of Power
Greeene, Robert - The Art Of Seduction
Strauss, Neil - The Game
Machiavelli, Niccolo - The Prince

please add the ones you think are good reading material

The natural-richard la ruina aka gambler.

The Mystery Method - A must read for someone new to the game. Or anyone who has not read it.
The Juggler Method - A complete contradiction to Mystery's advice.

I highly advise reading both. Then taking the good aspect of each and incorporating them into your game.

In a nutshell:
Mystery Method:
Look at me, I'm a stud. I don't need to say I am. You can tell I'm a high valued male by the friends I have (or can fake), the clothes I wear, and the way I carry myself.

Juggler Method:
Don't look at me. Talk to me. I'm a cool friendly guy, that is fun to be around. After you talk to me, you will think I'm the cool the brother it is ok sleep with with, because we're not related.

Also, anything David DeAnlgelo is mandatory as well.

EDIT: the mystery method also does a great job of breaking down game into logical steps so that it is easy to measure progress and set goals. IMO, the best way is to use Mystery's method, and take his advice. Then incorporate other material from other PUA's into that.

I'm not saying Mystery is the better than other Master PUA's. Just that he did a great job of turning pickup into a science that can be taught.