The most annoying thing passengers do is.....  snap their fingers to get the attention of flight attendants.

Researchers surveyed 700 airline workers in 85 countries to get the list of gripes about passengers.

Also annoying is when passengers try to exit the plane before the pilot gives the signal.

The top most hated passenger habits include:

1. Snapping their fingers to get a flight attendant's attention

2. Trying to exit the plane before the pilot gives the signal

3. Stuffing too much in the overhead compartment

4. Complaining about the lack of space in the overhead compartment

5. Talking through the safety demonstration

I read this article at latimes.com