#3: People who knowingly ruin films for others.
I overheard a conversation on the bus the other day. It went something like this:
"Did you watch that Slumdog Millionaire last night?"
"No, was it good?"
"Oh, yeah. They had a hell of a time, the little kids. I felt sorry for them, but then he won the millionaire quiz at the end so it was alright. They shot his brother, though. Shot him in a bath. The gangsters did."
Is this how you recommend a film to someone? By negating the need to actually watch the film? Do you think you're doing them a favour? They missed the film, not their child's first words! You don't need to fill them in on the important bits!
The person I overheard wasn't doing this deliberately, I'm sure. The spoilers were delivered in a gossipy, "you'll-never-guess-what-I-saw" manner, as if imparting some astonishing secret. This is not always the case.
I have a friend who takes pure, sadistic pleasure in ruining films for people. If you said "I'm watching "The Sixth Sense" for the first time ever tonight. Have you seen it?" His response would be "Yeah, The twist is: Bruce Willis is dead." No witty hints or humourous attempts to feign accidental revelation, he will spoil a film for you just to see the look on your face.
I'm sure there is a psychological reason for this phenomenon; something to do with "need for control" or "sadistic, malignant narcissism" or summat, but I prefer to call it simply annoying as shit.