Geez Andrew, keeping it to three is tough. I'll have to generalize. Keep in mind each one could be broken down into dozens more.

1. The ever diminishing lack of respect, courtesy, manors, values, morals, etc.. by an ever growing number of people regardless of whether you are in your car, at the store, online, on the phone, etc...

2. Self-righteous and arrogant people who know it all.

3. Nappy-headed ho's (just kidding).