I love the story and environment aspect in games, in all media in fact. Games are great for this as the environment can be just as detailed as in books or movies but you interact with them. Games that I own include HALF-LIFE 2 and the rest of the orange box, COD4, L4D, Audiosurf, Half-Life, C&C 3, AOE III, CIV IV, and a bunch of older strategy games. I am strictly a source modder at the moment. I am still a beginner in hammer but am experienced with architecture/displacements, triggers and basic logic work, basic ai, and a bit of scripting.