I'm not just talking about ones you enjoyed. I'm talking about ones that made an impact on your life. Ones that you could watch over and over again.
Mine would have to be Secondhand Lions. My ex and I stumbled across it on pay per view one day, and ordered it knowing nothing about except the little description. I loved it. Ended up recording it for my parents and they loved it too, that tape has been passed around the family so many times.
Also The Princess Bride, Excalibur, and the Japanese movie Audition (though it's impact was for an entirely different reason).