This is a brilliant idea for a thread. I might just discover a hidden word-count limit for these forums. Let's see ...

Taxi drivers who deliberately take the long way or the route that will have them bogged down in traffic for half an hour because it'll rack up a few more dollars on the meter, and then pretend they didn't realise when you call them on it.

Kids who annoy the grown ups because they (the kids, that is) think it's cute.

Weak people. Those who do something not even mildy challenging and then winge, cry and complain because they're out of their comfort zone.

Ignorant people who are so ignorant, they actually think they're especially clever.

Politicians and anyone else who spends more of his or her working life justifying his or her existance than actually doing something practical.

Former Australian Foreign Minister Alexander Downer - the Aussies know what I'm talking about; one look at him, one syllable from his snotty, whiney voice box and you will be overwhelmed with a burning desire to slowly torture him to death.

Officers - anyone who's ever been an enlisted member of any military will understand.

Now, I haven't driven a car much during the past couple of years, but some of my previous pet peeves would include:
People who break every road law in the book to speed past you on a straight stretch of road and then can't even manage a reasonable speed around the corners up ahead.
People who drive into an intersection even though the traffic's backed up on the other side and they know they'll end up stuck in the middle of said intersection when the light goes red, causing havoc for the drivers who now have the green light.
Blokes who drive "big" cars for no other purpose than to compensate for their inadequate manhood. This especially applies to anyone who drives a Hummer.
Teenagers who drive a pissy little Korean car and think it's some kind of high-end sports car because they bolted a four-inch muffler and a formula-one spoiler on the back.

That'll do for now. I'm getting angry just dredging these up.