1. useful :http://www.thingiverse.com/thing:42948
I think this iPhone case is pretty useful. It protects around the side of the iPhone and has very beautiful design in the back.
2. artistic/beautiful :http://www.thingiverse.com/thing:23716
It is a beautiful building design. It looks very complex.
3. pointless/useless :http://www.thingiverse.com/thing:42249
I think this is useless. We don't need a 3D recycle symbol.
4. funny/weird: http://www.thingiverse.com/thing:42947
A funny design, but it is cute.
This is a strange design. A little bit scary too.