Leia and Han. They go through a harrowing series of situations, gradually progressing from mutual annoyance to the end, where he's about to be frozen in carbonite, and she says, "I love you."BTW How is The Empire Strikes Back romantic?
He responds quietly, "I know."
Some fans laughed at this exchange, but it wasn't meant to be funny, and Harrison Ford refused to treat it as funny.
It's a far better romance in that franchise than anything else they offered.