Are there any wiz bang great graphing tools out there besides Excel?

I just mean in terms of graphical representation.

free or paid for?

Oracle is basically the standard, but its pricey.

GNUplot can be made to do some reasonably neat things but its a pain to use. Is free though.

A few of my friends use SigmaPlot, I havnt used it but they seem to like it. Again its a pay for job.

SPSS is a standard tool for windows bods doing stats stuff which has good statistical graphing functionality.