Yes, I tried Panopticlick on a number of different computers and it was always the fonts that gave them the most bits of entropy. I wonder if installing a couple of new fonts and deleting a few others (which I do from time to time) would make them believe I'm a different person...

But really, browsers should stop allowing scripts to access the full list of available fonts. What use does a website have for that data, anyway? Any site that doesn't want to use one of the standard fonts should be using webfonts nowadays.