Side by side analyses in Stata, SPSS, SAS, and R

I've linked to UCLA's stat computing resources once before on a previous post about choosing the right analysis for the questions your asking and the data types you have. Here's another section of the same website that has code to run an identical analysis in all of these statistical packages, with examples to walk through (as they note here, just because they don't list code for a particular software for an analysis doesn't mean the software can't do it). They also have examples of power calculations for a smattering of statistics using previously mentioned G*power in addition to others.

UCLA Stat computing - data analysis examples with Stata, SPSS, SAS, R, and others