Hmmm, my top 3 pet peeves:
1. Being forced to smell others' cigarette smoke. Yes, you made the choice to smoke, but I should have a choice to breathe fresh air too.
2. Dishes. 'Nuff said.
3. When someone puts something inches away from the location it was supposed to go to. For instance, trash on the counter, instead of in the trash can. You get the idea.

I just answered this Featured Question, you can answer it too!