Smoking. I find smoking very annoying and can't stand smokers. It beats my imagination why people smoke knowing fully well smoking is dangerous to health. I feel smokers are not considerate like they don't care if they live or not as long as they satisfy urge. It's not fair to their loved ones. I wish smokers will quit smoking for the sake of their loved ones. So, smoking is one of the habits that other people have that I find so annoying. Please no offence to anyone
Dirt. I so much hate a dirty and unhygienic somebody,i can not leave with such person it will be so disgusting.
I think usually the most annoying habits are the ones I see relates with a person's hygiene. I had a friend who did not like to bath at all. It made the place smell really badly.