Sleeper

The thriller genre? Or the person next to you? Close to you? Actually a "real" sleeper wouldn't even know themselves now would they? But this is quite straight forward thriller stuff. And while I am fond of the main actress in this (not just visually speaking), it is not like she will hold your attention for the whole movie or run time.

Cliches come and go and I would think that most will be able to predict where this is going, even before it shows us any hint of that. Still I've seen so many other movies that are worse than this ... a tv thriller, that might float your boat then