Systat Software, Inc, sells a comprehensive statistcal package called Systat. (They also sell Sigma Plot, a scientific journal-quality grahics package and Sigma Stat, another statistics pakage used in many basic science labs.)
They also provide a free version of Systat, called Mystat, that can be downloaded here. It does not include all features of Systat. Notably, survival analysis, study size/power calculations, pairwise comparisons in ANOVA and complex versions of ANOVA are not included, but it does have most other basic analyses. It also includes a lot of graphical capabilities and good help facilities for both the software and statistics itself.