Singing in the Rain, especially the bit where Gene Kelly is dancing up the street and stamping in puddles in the rain. My mum and dad took me to see it when I was a kid, during the Festival of Britain, if my memory serves me well.
Okay, I can't help it... The Wizard of Oz! For a movie made so long ago, it truly broke the rules. I remember watching it in both a weird eerie kind of way and with amazement too! My father recorded it on Halloween night in the early 80's and I watched it a couple of times a week! I know have a Wizard of Oz collection that I will have to pass down to my daughter who has the same bug as I did!
Ooh, "Never Ending Story", yes another good one... I had some ugly necklace that looked like the symbol on the book in the very begining... I used to wear it and pretend (to myself) that it came from the story :-)