1) Calling something "g@y" to mean "I don't like it"
2) Calling something "Retarded" as a synonym for "g@y" when I tell them to knock it off
3) The kids who axe me to borrow them a liberry book. Yes, I have gotten all three of those in one sentence.
4) My DH's grandmother, who says "PO-leece" and "SEE-ment" and other atrocities against the English language. My FIL does this sometimes too, and I have a very hard time not giggling. That's what you get when you live in rural Kentucky for 75 years, I guess, but it makes me cringe every time.
5) People who disguise raisins or carob chip cookies as normal chocolate chip cookies, then try to pass them off at a holiday gathering. We can TELL the difference, people, but not before we bite into it and get a mouth full of raisin! Yuck.