Critics apparently hated Brotherhood of the Wolf, and reviews of Se7en are strangely mixed. This confuses me, since I love both movies. The martial arts alone in Brotherhood of the Wolf is worth whatever the disc costs now (almost nothing), and the story is very competent, combining different film genres very well.
And Se7en is, well, Se7en. Telling me Se7en is a bad movie is like telling most people that The Godfather sucks.
And then there's Gattaca, which people liked but very few actually saw. Same for ExistenZ. It was unfortunately released at the same time as The Matrix, and so was overshadowed (despite being a far better movie and particularly relevant to gamers.)