1) People who say some equivalent of "How you doing?" as they whiz by. How rude is it to ask that question with no intention of pausing to hear the answer. That's been a huge pet peeve of mine for decades.
2) When people ask a question because they really want the answer to a whole other question. This happens a lot. Something like,
"Did Janet like the beach cabin?"
"Yeah, why?"
"Well, is she going back this weekend?"
"I don't know. Why?"
"Well, I was wondering if she's going to go to the movie with you."
"I don't know. Why?"
"Well, if she's going, are you going to ride with her?"
"I don't know yet, why?"
"Well, I want to go pick up my stuff at the dry cleaner, and I was wondering if I could use the car that day."
%%Then why was your question about whether Janet liked the beach cabin??%%