I will go old school and pick Dracula.

One other badass that I love is elijah price from the movie Unbreakable.
"Do you know what the scariest thing is? To not know your place in this world, to not know why you're here."
This son of a koolaid jar would kill thousands of people just to find his arch-enemy. Granted this is most likely my favorite movie so I will be a little biased.

Best hero of all time thats easy McGyver.....Or Leon from The Professional.......Or Inigo Montoya from the princes bride....forget it I dont think I can pick one.