There's no doubt that one of the key aspects of a paranormal romance is emotional conflict. A story can't be built around that alone, but without it, there would be no love story. Emotional conflict arises from something within a person which sometimes seems irrational and utterly insane. Okay, maybe not sometimes, but most of the time!
To create emotional conflict for the protagonist and their love interest, it must arise out of something apart from the plot. It must be something inside of each of them that would create the same conflict no matter where or how they met. Of course, it is intensified by the situation and the only way to resolve it is by working together.
Do not confuse emotional conflict with intellectual conflict. Intellectual conflict always starts in the mind. It's a conflict of ideas. A character might try to reason out their emotional conflict and make it intellectual, but it doesn't make it so. An intellectual conflict can be argued and the character can be persuaded to change their mind. Emotions aren't so reasonable. They simply are. There's no logic to them. Remember in a paranormal romance, the goal is to win the heart of one's love not the mind.
Do not confuse emotional conflict with external conflict. External conflicts arises outside of the character through plot and circumstance. Emotions make up internal conflicts and they arise within the characters themselves. Where emotional conflict make-up the heart of the novel, external conflict drives the plot. You can't have one without the other.
The key to writing a great paranormal romance is to meld the intense emotional conflict with an equally as exciting external one. If either aspect is lacking, the story will flop.
Who are your favorite authors in terms of emotional conflict?