There are many free data visualisation tools available on the web now. This is a roundup of some of the current crop which are making the visualisation of data easier and more creative.
Infogr.am is for data what Squarespace is for web design. It's interface is incredibly easy to use, and the options create visually compelling charts which can be interactive. The free version saves your charts to a web page. $18 per month upgrades your account so you can set up real-time data feeds and download the charts you create.
You can also add charts and information together to create interactive infographics
Try it out here: https://infogr.am
Sunburst Chart Generator
Here's a free online tool to generate sunburst charts. Sunbursts are used to present data that has a hierarchical structure.
The script is interactive, so you can roll-over different segments to see the relative popularity of different routes through the site being analysed.