I saw this film many years ago I think when it showed on Ch4 one night and I loved it. I know that Alicia Silverstone is most famous for Clueless, but as far I'm concerned, she absolutely shines in this, her motion picture debut as an unhinged, but extremely clever teenage girl with a crush on her parents' new lodger, who moves into their guest house.
Cary Elwes is excellent as the man who is tormented by Darian Forrester, and at first sees it as just a silly school girl crush and then quickly realises that it is far more serious than that and Darian is far more dangerous than that.
As with all great thrillers like this, a sexy villian is always needed, and boy, does Alicia fill those shoes with ease! Her expressions are spot on throughout and she is able to go from sweet and innocent to manipulative and deadly and furious in a flash and it is totally convincing. She also dares to show some flesh at such a tender age, (some might argue a body double, but with Hollywood, you never know, maybe they broke the rules this time, I don't care), and it makes the film even more sexy and gripping. She gets Nick (Elwes) into deep trouble by the last part of the film, but you can certainly understand how he could be drawn into her sadistic little game.
For me, this film outdoes overblown melodrama like your Fatal Attraction for example, which I believe is so overrated and stands up as a really sexy thriller, and without a doubt, Alicia Silverstone makes it as good as it is. I just think it's a great pity that she was never able to capitalise on it. But we always have this gem.