I like to think that I have a pretty high tolerance for things, but I admit I also get annoyed easily by little things...people not washing their hands after using the bathroom, eating with their mouths opened, smacking chewing gum. I'll spare you the full list -- but, there are two things that really bug me. They're phrases:
"Throw (me/them/us) under the bus."
"It is what it is."
I hate it. I cringe when I hear these two "sentences." Please if I'm around, don't say them. But if you do say them, I won't admonish you.