I've probably written this here before but when certain neighbors of mine don't say hello or good morning or just don't acknowledge me. It's very rude and hurts my feelings.
My pet peeves are
1. People offering opinions without knowing facts (EG people who believe the Cascio tracks are fake).
2. People who personally insult someone because of something they like (EG liking Lady GaGa and people rip on you for it).
3. When people ignore what you just said and reply to you with the EXACT thing you just rebutted :S
People who leave hate comments on youtube. Seriously what's the point? You go on youtube, type in the name of someone you don't like, watch that persons video (Which is only adding to that persons popularity on youtube anyway) and then you leave a hate comment. Wouldn't it be better to watch videos of things you do like?