One favorite recently watched again with the kids is The Princess Bride. Also love the book. So many fun quotes - my 10 year old goes around saying "anybody want a peanut". Actually that gets old after awhile :) One quote that I repeat often "Life isn't fair, but it's fairer than death".
Although sappy - I've watched You've Got Mail more times than I should. Meg Ryan is this cute little thing (yea I'd like to look like that) and the books and the dog - I do get teary eyed when I watch that one every few years.
And Colin Firth - I would probably watch him in commercials.