I've found jfreechart very useful, but for quite a long time I have been using other Java chart library for only one type of chart - spiderweb. Problem with jfreechart was, that this spiderweb doesn't have web lines and labels on value axis. Finally, I've looked on source code and noticed that this features can be easily added.
Here's my improved version - I've tried to make it easy to incorporate in next version of jfree.
Hope you like it. :)