The movie was not very good, but he was the perfect Heathclff for me because he has it all for that role, except dark skin but whatever.
Once I had a glimpse of Tom Hardy in a role of Heathcliff and no, just no. (I quite like Hardy, btw) And the newest adaptation I don't plan on seeing (it sucks) for a change has an actor with dark skin, but he looks like an adorable puppy so again it's a no in advance. Maybe Ralph didn't have the luck to star in the best adaptation of WH there is, but he's perfect combination of looks and acting, expressions, emotional range, good and evil, passion, torment, scary, etc. for playing this particular character.