Bram Stoker's Dracula (The original), a vicious, sadistic monster with no redeeming qualities.
Dracula from Castlevania, though taking inspiration from more sympathetic takes on the character, is also one of the most powerful iterations, being more of a god of evil than a mere vampire.
Dracula from World of Darkness, a magnificent bastard who went from mere mortal to fourth generation (A single generation under the Antediluvians themselves) vampire in a single night, with nothing more than his own cunning and intimidating presence.
Dracula from Buffy the Vampire Slayer, a deliberate homage to the classic portrayal giving him abilities standard vampires do not possess (Explained as sorcery rather than innate powers, which may mean old Joss did his homework, as the original story said the same), making him far more formidable than most vampires.
Nosferatu, for providing a different, spookier take on the character.
That's basically all I want to add.