Capote Why? Because it's actually quite a mean-spirited (and ostensibly true) story completely devoid of attempts to "happy-up" the ending.
Fast, Cheap & Out of Control Why? Robots, naked mole rats, topiaries, and lion taming. Very well edited, interesting people and topics. My only complaint is my ususal one: "There should have been more robots."
Rent Why? Because it provides a new lower bound in the universe - if Einstein had seen Rent, quantum physics would be a much more complete theory than it is today. Also now when confronted with movies like "The Postman," "Anchorman," and "National Lampoon's Christmas Vacation" you can sit back, relax, and enjoy the film for what it is. Simply say to yourself: "At least I'm not watching Rent."
:P