My Top 10
The Princess Bride
Darby O'Gill and the Little People - see Sean Connery before he was James Bond:)
Swiss Family Robinson
The Parent Trap (1961)
Back to the Future
All Pixar films
Most Disney animated films
Most Christmas movies
Many musicals (namely Annie, Newsies, etc.)
And quite frankly, I really like all the Harry Potter movies.
Though they appear in other lists I must also mention: Willow, Anne of Green Gables, and Anne of Avonlea (aka: Anne the Sequel).