Like any recruiter, I'd heard some really crazy interview questions. The worst one I've heard was "what's your favorite kind of music? Now, we're not talking about someone working at a record store or Christian radio station.........this was for an engineering job. Needless to say, that question does nothing to help evaluate an engineering candidate.
Why does this matter? A few things:
1) It's a waste of time! Other than breaking the ice, every conversation with a candidate needs to be helping you make a hiring decision. That's it, nothing else matters. When you are done with the interview do you want to hire this candidate? If the answer is "Not sure" but you know they like Snoop Dogg than you're missing the whole point
2) Stupid questions, give the wrong impression - Never get a second chance to make a first opinion.....riiiight. Image having an interview full of silly questions, would you want to work there? No way!
3) You're hire the WRONG people - This is the most important. Interviewing is a science and and art. You need to be consistently asking questions so you are calibrated to determine good or bad answers. Asking about musical tastes, or favorite book, etc are not good predictors of future success. By focusing on the wrong stuff, you're hire the wrong people and ultimately undermine your whole effort.
The point here? Don't ask stupid interview questions. Find out what the job requires, ask relevant and detailed questions....over and over again so you can tell the good candidates from the bad............and if the person you hire likes some form of music or book you'd never enjoy....maybe you should just open up, relax and realize that you work with these people, and that's it. What they do or enjoy in their own time...will most likely not impact their ability to perform in your company.