Very interesting your top five, in which there is one of my favorites "Strange Days".
The kind of science fiction, it is one of my favorite, takes us to the need to believe in the existence of some kind of mas there of us, I delight that every movie to his way tries to answer questioning many, but these answers there generates mas his questions which is wonderful, extraterrestrial life, virtual reality, alternative worlds, robots and trips in the time are topics that make explode our brain.
But to part of your top five, it is necessary to touch a curious topic that ocurrio at the end of the 90s, specifically in the second half, excellent years for the cinema of science fiction, where Will's Smith reputation I shoot, Bruce Willis entertained with classic his " The Fifth Element (1997) " and us skittle the brain with "Twelve Monkeys (1995)" and Sigourney Weaver was returning to the load with Ally, the resurrection (1997).
But certainly the milestone mas important and curious topic was "Matrix" (1999), with an original concept, special effects that they defined before and after the cinema of science fiction, his success was such that opaque others you praise productions of the epoch, of these works of the nineties darkened and that as the work of the brothers Wachowski, it shows us alternative realities, we can name in order of my preference:
1-Dark Side (1998) - Included in your top five
2-Gattaca (1997) - Included in your top five
3-The Thirteenth Floor (1998)
4-Contact (1997)
5- eXistenZ (1999)