Hereditary
Nothing says “I would destroy the world for you” like The Cabin In The Woods.
I like Love Actually, dammit.
Joe Versus the Volcano
Mr. and Mrs. Smith
Ninotchka
The 1935 version of A Midsummer Night’s Dream
The 1999 version of A Midsummer Night’s Dream
Whatever she picks.
A nice Bette Davis scorcher.
Her love story movies are quite poignant.
The best suggestion I have seen so far.
Attack of the Giant Leeches (1959)
Brian’s Song
She’ll be crying anyway and when she sees you tearing up (which you’re going to do), you’re in. Happy VD!
Casablanca
While You Were Sleeping is cute and not too challenging. And it’s amazingly romantic.
Terrible abbreviation choice 
L.A. Story
My Man Godfrey
Blue Velvet
No, it didn’t work for me, but I liked the movie.
I stole it from the More Jokes thread over in MPSIMS. You don’t think I’m clever enough to come up with that on my own, do ya? BAFF! 
ding ding ding - the correct answer.
The Testament of Dr. Mabuse
The Conversation
Meteor