I have so many that I love but if there's one that I would never get tired of watching it would be The Notebook. Or maybe Shawshank Redemption. And then there's Lion King....
The Grinch Movie~ with Jim Carrey~!! (& I almost never watched it years ago cause the cartoon Of it use to scare me when I was younger~ The movie made me laugh & Understand Better what it was all about)
Of course I have many others though XD but trying to limit them to one as requested. Totally agree with who ever said " The Princess Bride" and "The Lion King"
Hope and Glory (takes place in London during World War II and it's about the Blitz and a young boy's joy with having so many places to explore - many bombed out buildings. Then his own house gets hit.)