What film, show or game that is not necessarily 'underated' didn't have the level of social impact it deserved.
What's the antithesis of Arrested Development, Firefly or The Big Lebowski? Those may never have 'found their audience' but over time seemed to recognised by everyone. What are the deep cuts that you liked but it feels like everyone has completely forgotten they even existed.
Steins;Gate is one of those few shows I'd recommend which come with the annoying disclaimer "You need to watch until episode X and then you're in for a ride"
The first time I watched death note was because some local restaurant had it being projected behind the bar when I went to get a late lunch at 2 pm. I still have no idea why they had it running, but I watched like 5 or 6 episodes before leaving.