TOD
People who talk, crunch. crinkle, kick the chair, make and take cell phone calls in the theatre be it movie, play, concert, awards ceremony whatever
Tall people in front of you, in a theatre without sufficient rake, who insist on moving from side to side during the entire performance so that you have to keep sliding froom side to side in order to see anything other than their big fat head
people who look mortally offended when you point out to them that the people on stage (or screen) are what everyone has come to see and hear