He's had many enemies over the years, usually chief among them Professor Van Helsing (and his descendants), crossed paths with countless characters across various forms of media. One prominent example is Sherlock Holmes himself.
Dracula vs. Sherlock Holmes
Perhaps one of the Detective's first 'supernatural' opponents, the two have clashed on more than one occasion.
Literature: (short list)
"Sherlock Holmes vs. Dracula; or, The Adventures of the Sanguinary Count" by Loren. D Estleman. This story posits itself as the 'True Story' of Bram Stoker's book, Dracula. Holmes and Watson investigate the bizarre occurrences surrounding the largely abandoned ship 'The Demeter', and eventually cross paths with not only Professor Abraham Van Helsing (shown in this to be an equal in intelligence) but also incur the wrath of the Vampire Count himself. The events in this transpire parallel to those shown in Bram Stoker's book.
"The Holmes-Dracula File" by Fred Saberhagen, apart of the author's lengthy series dedicated to the Vampire Count. Dracula's return trip to London is cut short by devious minds intent on using his blood to create a plague with which they'll unleash upon the city during the Queen's Jubilee. It's up to Sherlock Holmes (and the Count himself) to stop them. Story is treated as one of the many versions of infamous/fabled The Giant Rat of Sumatra tale.
"Red Sunset" a short story by Bob Madisen, collected in the anthology book "Gaslight Grimoire: Fantastic Tales of Sherlock Holmes" has an elderly, retired Holmes (relocated to the States during WW2 for his own safety) aiding a Sam Spade-esque gumshoe in solving a most peculiar case involving what is soon revealed to be vampires, created by another immigrant... Count Dracula.
"Scarlet in Gaslight", a 1987 Eisner Award nominated comic written by Martin Powell has Professor Moriarty coerce the Vampire Count into coming back to London, intent on using Dracula to plunge the city into darkness and help rid him of Sherlock Holmes. From the foggy streets of London to the Reichenbach Falls, this tale takes quite a few twists.
"Victorian Undead II: Sherlock Holmes vs. Dracula" the 2011 sequel to the popular Wildstorm (DC Comics) story "Victorian Undead" (which had Holmes facing down a plague of zombies being unleashed upon London), pits the Great Detective against the Vampire Lord himself. Another story that treats itself as an alternative take on the original Dracula story.
- Count Dracula on Wikipedia.