Just for fun and discussion, here's an alphabetized list of relatively recent speculative romance movies and my thoughts on how they'd fare as romance novels. One of my requirements, in order to cut down on the list, is that the movie have a relatively standard HEA, so Ghost, The Ghost and Mrs. Muir, and Somewhere In Time, though enjoyable love stories, won't be showing up. Another requirement is that the romance has to be a major plot or subplot screentime-wise, so I won't list movies like the LOTR trilogy. That being said....
13 Going On 30: Jennifer Garner's character was 13 years old in a grown woman's body, technically, and the hero, a friend she'd been mean to in the past, was totally beta. While a bodyswapping premise has been used to great effect in spec romance, I don't think a heroine with a 13 year old mentality having the type of...adult relationships that take place in today's romances would fly. Sort of like Barbara Cartland chick lit, but as a movie it was cute. And I have a weak spot for guy next door heroes, who show up a LOT more frequently in romance movies than they do in romance novels.
Blast from the Past: The hero and his parents locked themselves into a fallout shelter by accident and sent the hero into the outside world to find supplies when he was grown. The hero is a boyscout character instead of a leather-clad, angsty growler, but the heroine was a good fit for today's market -- cynical, attractive and dubious about the hero, despite the fact he was an amazing dancer and...literally...kissed her feet in a surprisingly sultry scene. Technically there weren't any TRUE paranormal or sf elements, but as far as the hero was concerned, this was a futuristic romance.
Ever After: Cinderella story with an earthy, practical heroine and a slightly bossy prince who nevertheless becomes enchanted with our heroine after a rowdy cute meet. AND she maintains a dual identity for part of the movie, giving them a reason to remain romantically apart until the end. Yeah, I think this one could work as one of today's paranormal romances.