A few more just came to mind:

City street bikers.  They get mad when they run through a stop sign and you almost hit them while abiding the traffic laws.  If I were to hit one, I might have an initial feeling of joy before I freak out about what just happened.  Not necessarily happy joy, but like the first time you successfully enter the Contra cheat code on Nintendo.

People with poor bus-riding etiquette.  Move to the back.  Don’t cut in line when entering the bus.

People at work that print something, go to the printer, realize it’s out of paper, go back to their desk, print to another printer instead of refilling the paper.  I hate you.

Staples in the right corner. Where do people learn to do it that way?

Headphone guys at sporting events.

These Crock shoes. Guys look especially stupid in them.

The phrase “no worries.”

It just does.

Please don’t do this, you look stupid.

Mustard. It ruins meals.

Shirts tucked into jeans. Sorry, I just can’t do it.

Popped collars. I promise your neck is safe from the sun since that’s what you’re worried about.

I’m not an angry person, but someone’s gotta relate to a few of these. I’ll add to this section as they come to me. I have a feeling this will grow rapidly.

Bluetooth headsets in public. You’re not that important! Take it off when you walk down the street, chief. Please please please remove it when you’re at a sporting event, too.

Thank you for your cooperation.