Try one of the graphics-intensive ones, Copper or Web20. Either one is fine, as long as other styles remain available. The Informer style is hardly different from the Oxygen, so I don't like it.
Those are just plain awesome. The Web20 is my favorite.
As for the inclusion of the styles in distributive - I suggest adding just one alternative style to advertise the fact punBB can actually use them. I personally wasn't aware of it when I installed a forum for the first time.