I'll try not to get too into this as I've been obsessed with these movies since childhood, haha. Dracula starring Bela Lugosi will always be my favorite. I also liked the 1992 version with Gary Oldman, especially finally putting "the dead travel fast" in a movie adaption, but I didn't care for the ridiculous portrayal of Vlad Tepes, especially as they were trying so hard to not stray from Bram Stoker's intentions. Interview With the Vampire got my respects because in my opinion they did a better job with it in film than Ann Rice did with the novel, but the huge influx of "oh no, I'm a monster, I'm immortal, this sucks!" thing has gotten old, maybe I'm a purist. For pure creepiness Count Orlok the original Nosferatu, a Symphony of Horror beats them all in my opinion, something made in 1922 still creeps people out now.
I think it is John Carpenter's Vampire. And as for series of course True Blood, although Angel was also very good and had many surpising moments as well.
I don't think there are many good vampire films, but yeah I agree that underworld is probably the best.
I haven't watched it in a while but Vampires with James Woods would probably be the best B Level vampire movie.