News anchors who cannot speak clearly.

Typos in captions on the news, etc. Proofread, people!

Teeth sucking *shudder*.

Tailgaters.

People who don't use turn signals properly (either turn them on when not needed, or not use them when needed.)

People who diss my cats ("It's only a cat...")

People who cannot keep an appointment or commitment, and don't let you know.

People who are bigger nitpickers than I am.