As a kid I watched many films from my parent's generation. Mary Poppins (1964) or Great Escape (1963) come to mind as being staples every christmas -- Great Escape on boxing day especially
A generation before that people watched "It's a Wonderful Life" (1946) for much the same reason.
I've subjected my kids to a few old films from well before they were born, but they were films from my youth -- Bill and Ted, Back to the Future, Men in Black, Muppet Christmas Carol etc. And yes they've seen Star Wars, which was from before I was born (just), but that's an ongoing franchise.
I don't see them watching films from the 1960s like I did though, and I doubt they'll make their kids sit through films from the 90s.