Personally, Last Shift (2014). It was a smaller budget movie that came out awhile back that not many seem to know about. One of the only movies that actually got under my skin in recent years showing budget isn’t always everything. The director remade it recently with a bigger budget but you can skip the remake it’s not as good. Any other recommendations?
Threads (1984), imo there are very few films I think everyone should watch but that’s the one that most readily comes to mind.