Check out this article on Yahoo! based on a TripAdvisor survey...

Oblivious parents, body odor top list of travel irks - Yahoo! News

I've got one to add to the list:
PSYCHO TAXI CAB DRIVERS!

I have to say kids!! Most of my friends have children, some very well behaved, some total brats, all of them I care about-- so when I say this as someone who is Childless By Choice, I'm not intending to be cruel. PARENTS, IT IS YOUR REPONSIBILITY TO WATCH YOUR CHILDREN and teach them to behave with others in society. Children have accidents that can't be helped (such as throwing up on my expensive shoes on an airplane, and their ears can hurt terribly on a plane, NOT their fault), and some simply have Bad Parents that let them scream on the top of their lungs, or kick your seat non-stop during flight. I can take just about anything other than an obnoxious child invading my space, I see that as a parent failure.

I remember a friend of my husband telling him indignantly that it wasn't her responsibility to watch her 3 toddlers (she had a set of twins and a new child) at a restaurant, because that was "her" time. Here's a thought! Don't bring them!

(getting of of soapbox!)

I came online to wish everyone a Merry Christmas and I got caught up this discussion, LOL. Steve, Psycho cab drivers make the world exciting!