Bela Lugosi did not receive an Oscar nomination for portraying Count Dracula in Dracula.
The two elements of the film that make the strong cultural impact to be a classic of sorts are the opening minutes of the film and Bela Lugosi's performance as the Count. His performance was hugely influential with almost all parodies of Dracula based on Lugosi's work, but also many future performances took some stylistic choice from Lugosi. When Gary Oldman says "I never drink wine" in the 1992 version of the story you can easily see him calling back to Lugosi. Bela Lugosi's performance is one that creates this image of Dracula, an image to stand naturally within the darkness of his Gothic castle.
The best known image to Lugosi's Dracula is the hypnotic look Dracula gives to all of his soon to be victims. It is a perfect look that both captivates while suggesting the evil in his expression. Lugosi carries himself with an otherworldly quality that creates this undead monster as a most unique creature. Everything Lugosi does is slightly peculiar but fascinating in his peculiarity. The legendary line "Listen to them. Children of the night. What music they make." is given such a mythic quality to its delivery that suggests even more to the scene then what is ever shown.
In the scenes where Dracula is acting human Lugosi continues to be effective utilizing a certain allure and menace in his performance. These are the only scenes with Lugosi that don't heavily focus on his image and he has to more directly interact with the rest of the cast. Lugosi seems in almost another world in these scenes too although for a different reasons. Lugosi actually gives a performance worthy to function in the film. There is a certain presence and an energy that is just not found in the rather dull performances given by the rest of the cast.
Bela Lugosi's work as Dracula deserved a better film then this. Lugosi's performance honestly is underused in the course of the film, and the fact that his death is off screen is particularly egregious. The only scenes and moments of the film that work are the ones where Lugosi is present. Any scene without him seem to drag as there is nothing compelling about them. Lugosi though is able to at least bring something to a scene even if he only appears for a second due to the power he managed to create just through the mere sight of his Count Dracula.
Lugosi is not the best part of this film, he is the film. This film, without a doubt, would have none of its notoriety if it were not for the performance of Bela Lugosi. The first onscreen portrayal of Dracula came from Max Schreck as a rat faced horror in Nosferatu which was all about the direct terror brought on by the monster. Lugosi set a different standard with his portrayal of the blood sucker. Instead of the monster being a verminous plague, Lugosi set the standard that made Dracula an elegant charming terror who welcomed the victim to his deadly embrace.