Underworld Trilogy Movie (2003)

Underworld tells the story of Selene (played by Kate Beckinsale), a Death Dealer bent on destroying Lycans as an act of revenge against the Lycans that allegedly killed her family. She discovers that the Lycans are pursuing a human, Michael Corvin, for experimentation; Selene captures Michael herself to find out what the Lycans are up to. Along the way, Selene not only discovers a mutinous plot to destroy the Vampire Elders, but also a shocking revelation about her father-like Elder, Viktor.
Underworld: Evolution (2006)
Main article: Underworld: Evolution

After killing Viktor, Selene takes Michael to a Vampire safehouse and plans to return to Viktor's estate to awaken Markus, the last Vampire Elder. Before she can return, Markus confronts her, having been awakened by the blood of the Lycan scientist, Singe, after he was killed. Markus doesn't seem keen to help Selene and wishes to steal her memories for information. While on the run from Markus, Selene and Michael discover that Markus is the first Vampire, and that he plans to free his imprisoned brother, William, the first and most savage Lycan.
Underworld: Rise of the Lycans (2009)
Main article: Underworld: Rise of the Lycans

A prequel to the original film, Underworld: Rise of the Lycans tells the origins of Lucian and Sonja, a Lycan and Vampire that must keep their love life a secret due to their races. After Sonja's father, Viktor, hears of her pregnancy by Lucian, he orders her immediate execution to prevent a combination of the two races. This devastating event causes Lucian to lead a Lycan uprising against Viktor, thus bringing the start of a war that will last for centuries to come.
Like Vampire movies? Hell, this is your choice ;-)

Brilliant trilogy, recently bought Underworld: awakening, on dvd, selene now has a daughter, half vampire/lycan, i hope they make one more, kate beckinsale rocks!