Beautiful, unusual, powerful, easy-to-interpret statistical graphs

http://abeautifulwww.com/2008/09/08/20-useful-visualization-libraries/

Information Retrieval. Information Visualization. Data Mining. Artificial Intelligence. Web Programming. (by Todd Holloway).

The website was down last time I checked it, you can always do a search on Google for abeautifulwww.com if necessary.