I'm working on a web app for which I need to choose a free Javascript charts solution.

After doing some research I thought Graphael was the best because of the use of SVG and it seems quite low on resources. I also quite liked it because it enables to have some visually pleasing interactivity.

However someone just pointed out to me that Google Charts does the same thing. Would you agree?

As I'm not a developer I basically want to know which solution is best in terms of
- interactivity
- performance
- flexibility
- ease to implement

Which one would you go for?

Thanks in advance