From GraphPad Software:
GraphPad Prism, available for both Windows and Mac computers, combines scientific graphing, comprehensive curve fitting (nonlinear regression), understandable statistics, and data organization.
GraphPad Prism was originally designed for experimental biologists in medical schools and drug companies, especially those in pharmacology and physiology. Prism is now used much more broadly by all kinds of biologists, as well as social and physical scientists. More than 200,000 scientists in over 110 countries rely on Prism to analyze, graph and present their scientific data. It is also widely used by undergraduate and graduate students.
This review was originally posted on VersionTracker.com. This is one of the better graphing/statistical packages out there on the mac. Their technical support is one of the best I have encountered. Tech support has even helped me to understand my statistical results. Although the graphic capabilities are quite good, they really need to allow more complicated ANOVAs (e.g. 3-way) in the program. In addition, there is not enough scriptability built into the program. But even so, it's probably the best graphics/statistical program on the Mac. Don't even consider SPSS, use this instead.
This review was originally posted on VersionTracker.com. Easy to use, simple but efficient. It perfectly suits my needs. Very didactic software. Additionally, I really like their manual (I'm really bad at statistics and the manual is really descriptive and simple to understand).
A bit expensive though and I'd love to have easier possibilities to play with data formatting directly in Prism. More graph options would be much welcome too.