What is a truly fantastic but totally underrated film that should've been a massive hit but not enough people know about? I'll go first: About Time.
About Time is also maybe the all around best time travel movie ever made. Second one: Truly, Madly Deeply. It's perfection (and a master screenwriting class).
(I meant TMD as a second underrated film, not a second time travel film.) Also, no fair naming Oscar nominees. If it was nominated, it was not underrated.