Many classic movies are famous and important without being very entertaining to contemporary viewers. But others feel surprisingly fresh, in the sense that they still hold up as entertainment ... Which oldies successfully make you laugh/scream/cry/think on their own terms, without you having to put yourself in the shoes of bygone audiences?
In AskMe, Beardman asks about Oldies that don't feel like homework viewing, while in FanFare, Old Timey Film Club is announced, and Sunset Boulevard is posted as the group's debut thread (So they opened their big mouths and out came talk. Talk! TALK!).