The entire Total War franchise, excluding Total War: Rome II obviously, is currently on sale on the Steam Store for between 50-75%, depending on the bundle or game. So whether you are looking to improve your Total War collection, or have been holding out for the DLC packs to go on sale, now is your opportunity.
Currently you can buy Total War: Shogun 2 and its DLC for 50% off. Whilst the Fall of the Samurai stand-alone expansion is 75% off, and its DLC 50% off. The Total War Franchise Week sale will presumably last at least the length of the working week, if not a week proper. Meanwhile, for you Steam Card collectors and badge creators among the community each Total War game now apparently comes with support for Steam Cards, according to the Total War Facebook page.