I'm not talking about trolling or heckling, or being rude, just trying to gauge the proper amount of humor in responding.
Personally, I think a little levity adds to the site, and so long as the humor doesn't detract for the point, I see no harm.
An example of an answer with a bit of humor for someone asking an on-topic legal question (HR type question) and a person responds with "Other than being a very good way to be sued, no. Here's why.... (good, reasoned, detailed answer)
However, knowing how things can get out of hand, is this something to avoid and instead put more of a "Just the facts" approach towards things, or is it acceptable if it is limited and does not detract from the quality of a comment or answer?