If you are into role playing games where your character has free will to make its own choices as to how the storyline will continue and enjoy the vampire world, then you should try the Vampire the masquerade: Redemption although there is a bit of a romance in there too.. It's a bit old so I think your pc will probably run it
An old but amazing game was Oni , which is a great combat game with a good storyline as well if you don't mind playing as a woman...
If your pc can run Vampire the masquerade: Bloodlines that is the best game ever!! It starts with your turning into a vampire and choosing the Clan that you wish to be a part of. Each clan has its own skills and characteristics. They also have unique powers that are different for each clan. My fav are the Tremere which are the only ones using blood magic. Why axe your opponent's brains out when you can make his blood expode in his veins.. from a safe distance..
You choose how your character fights, swords,axes, guns, magic. you can choose whether you are a "good" vampire or a bad one.. how intelligent, persuasive , charismatic ect.. as you progress you earn exp points that you uses to raise your character's stats. you can even choose your own dialog and how your missions will end.
.. yes I love this game.. anw if your pc can run it...