Smooth!!
I used to keep everything pretty neatly trimmed with clippers; it just seemed like the courteous thing to do. However, I needed to shave my balls when I got my vasectomy and thought it was awesome! It's been my preference to keep them shaved (with razor) since then.
As far as women, I have a "less is more" preference. The closer to "less", the more likely I am to have a positive opinion as far as cunnilingus and just general appreciation. A bunch of hair will just ensure that I'm going to pass on cunnilingus and won't spend a lot of time appreciating the area. It's not a "right or wrong" thing, it's just what I've learned to appreciate. I have no doubt that if I were in my sexual prime in the 70s I'd have a different opinion.