Ink pens that won't write and dull knives.
And stupid drivers. (already mentioned) And people who take up more that a single parking space so no one can park "too close" to their precious car. Speaking of cars,
I saw a W.C. Fields movie once. He fell into a bunch of money and one of the first things he did was buy a fleet of cars and a driver for each one. He'd drive the lead car and the others followed right behind as he drove around town.
Whenever another driver did something to piss him off, he'd run 'em off the road, rear-end 'em, whatever... just tear their car the hell up. The "accident" would wreck his car, too, but he'd just get out, get in the next car of his, and off him and his fleet (minus one) would go.
I loved that movie! I think about it sometimes.