What Is The Most Romantic Song That You Have Ever Listen To?

Bed of Roses by Rex Benson and Steve Gillette.
https://aboutthesong.com/Blog/BedofRoses
Scroll to the bottom of the page to hear Steve Gillette and Cindy Mangsen sing the song, and some other interesting versions as well, including Kenny Rogers. Speaking of Kenny, Islands in the Stream with Dolly is another good one.

Dylan's "To Make You Feel My Love."

Covered by many, but my favorite by far is Mick McCauley & Winifred Horan's version on their 2005 album "Serenade." Merely sublime.

"Forever Autumn," Justin Hayward

"Romeo and Juliet,"  Dire Straits

"I've Just Seen a Face," The Beatles

This may get me banned from Audiogon, but it is our (my wife and myself) "dating song" that Adam Sandler sings to Drew Barrymore at the end of the movie "The Wedding Singer" called "All I Want To Do Is Grow Old With You".

The beshevleved mishappen raw simple innocence of it makes us cry every time.

’I Have Been In You’

Frank Zappa