Just a few things...
Road-users who won't indicate if they are turning left or right.
Adults who cycle on pavements.
Coffee drinkers who contaminate the sugar with coffee drips/granules.
Facebook users who list their occupation as "yummy mummy" - you mean "unemployed" right?
Facebook users who have rushed to decry this week's villain (currently Mark Bridger) as guilty, even if he's not been in court yet and not seen any evidence against him.
Drivers who tail-gate ... I do slow down by about 5 to 10% just to p*ss you off.
That indestructible plastic packaging which requires me to raid my toolbox for the tin-snips.
Those ridiculous FACT warning screens at the start of films. It does beg the question about why you would make a crappy camcorder bootleg, when you could download a studio-sourced bootleg via bittorrent.
Film distributors who send out their digital masterpieces to arrive at 1pm on a Friday, and then complain when the 1:10pm show is cancelled. We cancelled it because it takes a couple of hours to prepare a show for playback in this digital age.
Cinema patrons who talk or use their mobiles while the show is on. Plus one extra hatred point if it's an adult, rather than a kid.
Vanity number plates: Not big or clever.
Number plates using that German-style font, with an obviously British registration number: You're impressing nobody mate.
Any car with alloy wheels and painted drum-brakes: Cheap and not making any attempt to hide your cheapness.
Disk brakes on cars the diameter of milk-bottle tops: Why?
The use of the fonts Comic Sans or Papyrus. This will annoy me enough that I don't want to read your 'helpful' staff-room advice.
Web designers who think that grey text on a white background is easy to read.
TV manufacturers who think that reminding me that "Signal output from all AV terminals will be disabled during Media Player view" every time I use the USB port on the side of the TV is a good idea. No need Panasonic, I've read the manual.
A local council who hasn't yet replaced a stolen rubbish bin (reported three weeks ago) but wastes no time in threatening fines when I 'present waste' in black bin bags.
Ebay buyers who select the cheapest postage option, and then moan about how it took five days the item to arrive.
Any doctor or other medical professional giving me an injection who says "You'll just feel a scratch". No, it feels like someone is sticking a needle in me, and why are you telling me how I should feel about it?

(I know some of these have already been mentioned here by others, but this is my list)
(forkay, Sun 7 Oct 2012, 16:08, 3 replies)

We used to call the third one
"The Brown Crapper". It took us months to unmask the Brown Crapper in our student house. In the end it was Pete, the trainspotting physics student, who was putting a spoon wet with Happy Shopper coffee into the sugar bowl.

We never spoke again.
(rogerzilla, Sun 7 Oct 2012, 19:05, closed)

I enjoyed all that
But ripping off movies ain't so cool

If you ever had creative work ripped off you'd feel mugged. Trust me.
( spimf ™ is whoever you want him to be, Mon 8 Oct 2012, 0:44, closed)

Ripping off
I agree that ripping off creative works is (simply) theft, but I resent that even a small fraction of my cinema ticket contributes to lecturing the audience - all of whom have paid good money to be there. The people who need educating are the uploaders.
(forkay, Mon 8 Oct 2012, 5:39, closed)