1) The Santa Claus
The sequels were all terrible, but I have very fond memories of watching this film as a kid. I watched it again this Christmas and it still holds up. Plus I could watch that scene where the step dad gets the weenie whistle over and over and over again.
2) Hocus Pocus
3) The Secret Garden
This last one was hard, I almost went with A Little Princess, but I figured I'd see that one pop up in other places more than Secret Garden, so I went with this one. It's still very enjoyable for an adult. Beautiful scenery, and a very sweet story.