The love story between Mina and Dracula was preposterous, even for a fantasy film. I really don't see why this girl was worth saving from undeath.
I think a lot of it can be explained by vampires having some kind of supernatural seductive ability. Dracula's brides and Lucy appear to have this effect on men, and even Mina briefly starts to seduce Van Helsing.
I liked the movie. I wasn't wild about Hopkins's performance. He always is a bit over the top in my opinion. Gary Oldman did some interesting things with the character of Dracula.
I agree that he was over the top, but I actually found him very entertaining.