Right, actually Science Fiction is my favorite genre, however most of these popular "sci-fi" films that become blockbusters are the kind that are more centered on visuals and action rather than using science fiction as a tool to explore different philosophical aspects of life and human nature (like Blade Runner, Gattaca, Arrival and Ex Machina).
Some films somehow manage to combine it all: a great, intelligent plot, amazing visuals and thrilling action scenes and become popular favorites (like Inception), but unfortunately for most films it takes a certain "acceptance period" before they get the deserved recognition.
V for Vendetta is indeed a great film but I am not sure it fits the "underrated and hidden" criteria that I intended for this section... ;-)
Thanks for your comment, @cryptonet!
Check out Cloud Atlas. It was deemed unfilmable yet they made an amazing work of Art with it. It was also the biggest independent movie production ever.
@vimukthi I have seen it. It is indeed a fantastic visual extravaganza, but strangely I didn't manage to fully connect with the film; I feel that the project was a bit too ambitious and ended up falling short. However, I much prefer this kind of adventurous approach to film making than the usual Hollywood crowd-pleasers.