A pirate's favorite statistical package

Many social science researchers are familiar with a program called SPSS. SPSS was the only stats software I knew about when I came to grad school, and while I had some great experience with it and felt I knew how to do T-tests and ANOVA's really well that was it. In fact, my first semester that was all I needed to do anyway. The class I was taking was Quantitative Methods I (Univariate Statistics) and we spent a lot of time on T-tests and ANOVA doing them both by hand and in SPSS, both of which I had done as an undergrad for Dr. Bloom so I was more than prepared for the class.
This second semester however has been multivariate statistics and it has been awesome. First off we do nothing "by hand" we use SPSS or my new favorite program, R. R is an open source freeware statistics package that is almost entirely command-line driven. I like it because it tells me more about what it is doing (as opposed to SPSS) and since it is open source there are lots of user-defined functions that are available. I even like it's graphing functions better than SPSS. Here is a comparison of the same data, graphed by R (Right) and SPSS (Left). The only downside for R charting, IMHO, is that it is difficult to add a legend. But I've been working with different ways to do that and I think the final chart for my upcoming data analytic project will be quite appealing and informative.