I *loved* the first movie. I was always a fan of vampires and have played Vampire: The Masquerade for years, and yes Underworld was a fairly transparent "adaptation" of the White Wolf vampire mythos. (There was even a lawsuit about it at the time.) But Underworld brought plenty of its own original creativity to the scene, as well as a very beautifully crafted symbiology, if you cared to look for it.
Something that was quickly apparent to me was the dichotomy of vampire/feline/female to lupine/canine/male tension that these two species will always share; they are both weaker species without the other, but they cannot coexist without conflict. I loved all the ways they portrayed vampires as catlike, whereas the lupine/canine overlaps were naturally more conspicuous. And they REALLY nailed the complexities of Kindr--oops, I mean vampire politics and intrigue. I loved the subplot of Erika's infatuation with Craven and her two-faced duplicity while pretending to be Selene's friend. She was dangerously ambitious, very politically aware .. the kind of character I loved playing in V:tM. That's the kind of stuff that hooked me on Masquerade.
I also loved the art direction in the film, and both Bill Nighy and Kate B were perfect for their roles. (Bill Nighy was SO Ventrue. I loved him. Looking forward to the third movie to see more of him.) Something I particularly found amusing was that Kate had a great deal of weapons training for the role, much more than Carrie-Anne Moss got for her role in the Matrix. I believe it was mentioned somewhere in the commentary that Kate got to be so comfortable firing her weapons that she trained herself not to blink at the muzzleflashes, whereas the Matrix characters wear sunglasses at all times, even indoors, which helpfully covers up the actors' blinking.
The second movie wasn't as good as the first one (because it had less intrigue and more Lara Croftian adventure type stuff. Which is okay, made for a watchable flick. Pity about the silly Hollywood ending though, and what was up with that shamefully obvious miniature of Corvinus' boat?
/as