Inspired by +Peter V. Dell'Orto post
GURPS Classic Vehicles 3e - Because I plan to work on some 3d galleys and simple naval combat rules for my Crusades game (which has returned me a TON of notes, testing it with 3d model to see if the geometry is close to right). Bringing down the barrier to have naval engagements in your GURPS games. I already finish my Galley creation spreadsheet and just need time to arrange the articles and model the ships.
GURPS Social Engineering - Because I like living on the edge lolz. Social Encounters are the most unbalancing and unfamiliar terrain to most gamers and because of that tensions are much higher. The satisfaction of being able to outwit the enemy is also very satisfying and addicting. Aso Ideas how to organize and resolve Social Encounters.
GURPS Classic Conan 3e - The only Fictional Setting I will learn (I typically use Historical Real world settings) and this is going to be my "Go-to" fantasy setting now that it is PUBLIC DOMAIN!!! Whohoo! Conan is the really old school Fantasy lolz (Will definitely make a hard copy of this book). I can use all my research from other historical settings for this game.
GURPS Template Tooklit 1: Characters - After buying it It helped me refine my Article ideas to bring down the complexity barrier for gurps and make it easier for people to get into the game. A lot of ideas.
GURPS Horror 4e - trying to level up my story telling. Since I'm a big fan of GURPS Mysteries, horror is another set of complimentary skills.