I've had nothing but problems with GD::Graph. In particular, I found it very hard to colour charts the way I wanted - and judicious use of colour can make your charts a *lot* more readable.

So I wrote my own at work, based on PostScript. Sadly it's not Open Sores (yet), but it's very good :-) PostScript::Simple's arc method makes pie charts very easy indeed. 3D is a little tricky, but nothing that can't be solved by writing the PostScript yourself.