There are plenty of websites you can go to if you want humor - SO is supposed to be about providing useful answers to useful questions.
That's why I also vote down the "What's your favorite data structure"-type questions.
They add little of value to SO - if they were phrased as "What's the best data structure in C++ for representing a phone directory", that would be ideal.
I think the powers that be have basically stated that a small amount of programming-related humor is acceptable but they don't want the site being swamped.
What I tend to do is look at the content of my "answer". If it provides useful information, I make an answer out of it, even if there's a little humor - see herehere for example. If it's all humor and not really useful, I'll either put it in as a comment (likely) or just move on (less likely, due to my personality type).