For another good but disturbing movie..
The Voices.
Ryan Reynolds doing a rather outstanding performance as that slightly odd guy striving for normalcy in a small town, while doing his 9-5 job. Only to turn out to be a wee bit schizophrenic, with his cat and dog talking to him and offering advice. Things take a turn for the worse when his office crush stands him up on a date, then he accidentally kills her.
It aims for dark comedy, but it keeps sliding into very serious, dark areas as Reynolds character deals with the worsening situation while being oblivious on so many levels as to what he's actually doing/behaving. Then it'll turn on its head, have a rather out there comedy moment that jumps for the light, only to then twist back to the rather creepy and disturbing schizophrenic off his meds moment.
Gemma Arterton and Anna Kendrick help round out the supporting cast, and for the slightly bizarre, Reynolds actually does all the various voices of the animals that talk to him - A nice play on how they're all voices from his own head, even if the cat does talk in a murderous Scottish variation of his voice.