Show the interviewer that you work well with most personalities even though you recognize there are some folks out there who are quite difficult to please.
Think about that one person at work who is seen as hard to please. Perhaps there is someone at work who tries to intimidate others. Talk to the interviewer about what made this person challenging and what their relationship was to you. Avoid speaking poorly of anyone and be sure to end your response on a positive note.
"I once worked at a locally owned shop where the owner was very demanding. When the owner would walk into the store, employees would announce over their headset system that the owner was in the building, so that everyone felt prepared for his entrance into their department. The owner had great intentions; however, his people skills were a little rough. I could see that he meant well, and I recognized that he wanted to do a lot of good things. When we interacted, I always took his feedback with the understanding that he didn't mean things as harshly as they came out."
"I once worked for an executive who was very difficult in meetings and with interacting with groups of others. I took it upon myself to help this person interact better with others. When she would bark orders, I would reiterate what she was trying to say to the group more professionally. It took some time, but she learned to behave in a way that made people want to work with her."