The best way to see more samples is to download the component and open the chart list in the back end. You'll have lots of samples you can experiment with.
Here's one that isn't in the samples. It's plotting some simple time functions, and updating every 15 seconds
And here's a pie chart of the most popular articles on this site. Note that this only includes pages generated by com_content. It doesn't include the many pages generated by MediaShop. The SQL here is simply "SELECT title, hits FROM jos_content order by hits desc limit 10".