"The Amateur is Considerate...never knowingly uses the air for his/her own amusement in such a way as to lessen the pleasure of others."

Of course the obvious ones are those who find  every opportunity to inject foul words into the conversation to  impress everyone with their mastery of the English language..

There are those who  feel the need to be the frequency Police.  Who seems to delight in Thumping their chest, dragging their knuckles and thrashing the branches while chastising another Ham for any small infraction of their interpretation of proper Ham eticate.  Doing so loudly and well beyond when the point has been made.. 

Then there are those who enter a QSO as a bully does in the school yard.  They don't follow protocol for recognition.  No, they just shove their way in and often take over the subject being discussed and start dictating who is to talk next acting as a net control with 3 people present..

There are those who purposely give false information.  Like "It is illegal to tune up on the air, tune into a dummy load."  And become argumentative if they are called to task that the FCC rules permit one way transmission on air for tuning of equipment.  How would you expect to make your Pickup run better by tuning up your car.  By the same token, how would you bring an all band antenna into tune for the  frequency by switching off the antenna and tuning into a dummy load. Makes one wonder how they passed their Ham test.

Then there are the "Good Ole Boys" who  will try to run you off a frequency when you try to use a frequency not currently being used, claiming some type of ownership.  Which by the way is illegal to do as set forth in the FCC rules.  No one owns a frequency, if not in use, any Ham has license to use it.

There are those who evidently are not intelligent enough to carry on a conversation and resort to unidentified transmissions of usually vulgar interrupts.  Would it not be cool to have their Mommy look over their shoulder while they were engaged in this activity and ask them, "Son, WHAT ARE YA DOING?"  She would probably have to change their diaper after startling them..