Vampire: The Masquerade - Bloodlines
A visually stunning first-person role-playing adventure that combines intense first-person action with an open, non-linear world, rich character development and an immersive storyline. Built using Valve Source Technology - the same game engine technology used to power Half-Life 2.
Vampire: The Masquerade - Bloodlines is based on White Wolf's pen-and-paper RPG series, and developed by renowned RPG developer - Troika Games.
The game plunges players into the dark and gritty vampire underworld of modern day L.A. as a creature of the night, interacting with and battling mortals and other creatures of darkness with an incredible array of vampire powers, skills and traits.
Metacritic average of 80 http://www.metacritic.com/games/platforms/pc/vampirethemasqueradebloodlines?q=vampire%20bloodlines
And please note this was buggy on release which may have lowered scores a little. In fact the developers folded soon afterwards, but the title is very highly regarded and has now been patched up.
This title is regularly priced at £14.99-19.99 (and yes, I am talking digital copies), so this was just the bargain I'd been waiting for.
Trailer ;-) http://www.youtube.com/watch?v=xL90iPahGko