Bloodrayne - A campy third-person shooter where you play as a female vampire fighting Nazis during World War II. Gameplay can be clunky and a little frustrating in certain levels, but you'll usually be having too much fun to care. Wall-to-wall gore, but that's kind of the point.
Doom 3 - The black sheep of the Doom series, in part because it placed a stronger emphasis upon survival horror and storytelling than run-and-gun arcade shooting. Certainly not without its flaws - among other things, the level designs are dark and repetitive, and there's too much reliance on jump scares and monsters popping out of hidden doors - but it still has a story to tell, enjoys strong voice acting, and looks visually impressive nearly 20 years after its initial release. The GOG version also includes the remastered BFG Edition, which comes packaged with ports of the original Doom and Doom II, so you're really getting four games for the price of one.
The Vanishing of Ethan Carter - A little gem of a game that's part of the "walking simulator" genre. You play as psychic detective Paul Prospero, investigating the strange disappearance of a boy and his family in a rural Wisconsin town. This one is all story, with no enemies to fight; all of the emphasis is on exploration and solving the mystery. Absolutely gorgeous visuals, with a soundtrack to match.
Carrion - John Carpenter's The Thing, except you play as The Thing. In this bloody action/puzzle game, you're a shapeshifting alien attempting to escape from the underground lab where you're being studied. Evade traps and armed soldiers, eat people to regain health, and acquire fresh DNA samples to expand your range of special abilities. Lots of Metroid-style backtracking as you gain access to new areas, so keeping a map handy might be useful. There's no dialogue in this one, and the story is told entirely through cutscenes. Also includes a brief Christmas-themed DLC.
Zombie Night Terror - Lemmings, but with zombies! This game is a love letter to classic horror films, with most of its graphics in black and white, with occasional splashes of bloody red and slimy green. There is a story, sort of, but this one is a puzzle game first and foremost, as you try to guide your zombies to safety or direct them to kill all the humans in a given area. There's a complex variety of gameplay mechanics to be learned and mastered - all of your zombies have different skills to help you reach your goal - and it can be challenging, but don't get discouraged; beating a tough level feels very satisfying.
