X-Files features the exploits of FBI agent Fox Mulder and his partner Dana Scully. They investigate "X-FILES" which are cases with supernatural overtones. As a child, Mulder's sister was abducted by aliens and he has been trying to find her ever since. Scully is a scientist and medical doctor, so her natural scepticism is a good foil for Mulder's "I believe" attitude. With it's eerie theme music and thought provoking scripts, this was a top notch thriller series.