Ich bin ein Über-Geek
One popular statistical software package in academia is Stata. CGD has always used it, and thus so have I. As my colleague Mead Over pointed out, Stata's business model is an interesting mix of private and public goods provision. The private corporation profits by cultivating a public free-software community on top of its core product. Stata sells you the main program, which includes commands to perform all sorts of analyses.