Edit 2007-11-23: Is it normal that my guy that sit on my right is cutting is nails? -_-
When a "person" makes a lot of unpleasant noise sipping his/her drink. Almost everytime it happens with hot drinks. When a "person" produce a lot of strange sounds with his/her mouth chewing. When a "person" fart and/or burp in public without begging for pardon. ... In general, I hate who is not well-mannered. At least, in public and/or in a place where not everyone is a close friend.
Probably will sound strange for people that know me personally, but I think is different when you make it "on proper/for fun" and when you are in that way.