My favorite question as an interviewer is "What's your favorite OS of all time and why?"; the what is almost irrelevant and there are no right or wrong answers, but the whys are always useful/interesting (my favorite is probably a guy who raved about AIX's apparently amazing backup functionality).
I raise you a "I like SuSE Linux because it's free". To this day I don't know what to make of this answer. But that was only one of many answers that led to us not continuing with that candidate.
That day I changed my stance "there are no wrong answers", but I've also asked this in the past and it can yield some good conversation material.
