Does anyone know a pc game with an epic story?Quick best?

my config now is amd athlon 3000+ 1.8 ghz 1 gb ram with a video card of 512 that suports pixel shader 3.0 but i want a game that can be verry emersive like vampire bloodlines with medium graphics with the option of free multiplayer so 1st one who gives me what i want gets best :D!!!