Vampire®: The Masquerade-Bloodlines™ delivers a new type of RPG experience-one that blends all the core elements of a traditional RPG with the graphical richness, immediacy and brutal combat of a first-person action game. The game plunges players into the dark and gritty vampire underworld of modern-day L.A. as a creature of the night. Players will develop their character's powers, interact with other characters and embark on story-driven quests as they battle mortals and other vampires with an incredible array of vampire powers and weapons. Powered by Valve's Source Technology, the game is based on White Wolf's popular Vampire: The Masquerade pen-and-paper RPG series and its official clans.
http://store.steampowered.com/app/2600/
This RPG has easily one of the the best character animations and voice acting, a great story to boot and a wonderful, varied cast of characters, you are in for a ride.
Think of this game as a Vampire-based Mass Effect, but with better characters, better voice acting, better animations, better story, more meaningful choices and some of the best writing ever.