www.dotnetcharting.com
I don't have a very warm track record with third party tools. In general, I have found most of them to be pretty complex to use and time consuming to learn to the point where it isn't worth me pursuing them.
So I downloaded the developer trial of dotnetcharting's component with pretty low expectations...
I WAS WRONG.
I had this tool installed and a simple sample chart up and running correctly in less than 20 minutes. Very impressive. It even has a drill in feature. I did a very very basic drill in, so I'm not sure how customizable or complex you can get but the basic drill worked well.
I plan on purchasing a license for this for my business website once I find that first customer. (developer edition is free)