I'm not talking about new movies that you write off b/c you lost faith in the filmmaker or hate the actor or even just didn't like the trailer. Rather older films (at least 3 years) you like or love that you think people should watch but don't because it was panned or not well received at the time.

For example:

Elia Kazan's The Last Tycoon. Although not his best work, it's by no means a terrible movie and I loved it. And any chance to see Jack Nicholson and Robert De Niro (at their peaks by the way) in an intense scene together is well worth it.

I'm not talking about hidden gems. I'm talking films that got a decent release but audiences never went for it (either critics or bad timing for subject/actor(s)/filmmaker) and have stayed away ever since.