Reddit reviews 36 Dramatic Situations - Georges Polti

The Art of Game Design - Jesse Schell is very very good.

Game AI (Millington and Funge new edition iirc) is very very good.

Some non-game-design books that are very useful for those doing game design:

Scott McLoud: Making Comics (the other two in the series are good but the section on plot, characterization, and development in this one is great)

Donald Norman: The Design of Everyday Things. (How design works and how people interact with technology and...)

Christopher Alexander et al A Pattern Language: Towns, Buildings, and Construction (Thinking about scale and design elements and modularity and...)

Kevin Lynch: The Image of the City (How do urban spaces work - essential if your game is set in a city - how do people actually navigate)

Polti: The 36 Dramatic Situations (old, quirky, examines how there are really only a few human plots)

Matt Frederick: 101 Things I Learned in Architecture School (how to think about and execute simple art, improve your design sense, ...)