I´d also like to +1 for R. It might not be as easy to handle as STATA or even SPSS, in particular for non-programmers. Though I guess the average stackoverflower is way more of a programmer than I am.
That being said, i´d like to give a short overview, because I have seen a couple of statistical packages from a users (economists( point of view.
STATA is still the choice for the majority of economists, and indeed it has some pluses. STATAs GUI helps to stay in charge of a load of options and statistical functions. Besides STATA appears to be only package which has a mailing list that comes at least somewhat near to the benchmark: the one-of-a-kind R Mailing list. Still one could write sophisticated .do files or download some from the web.
STATA might not be as close to a programming language as R but still offers a nice programming language for statistical purposes. Depending on the size of you datasets you should check what license you need.
You could also use SPSS which is even more of a GUI Tool than STATA and is a little less comprehensive for example for econometric work such as TOBIT models or Panel regressions, particularly discrete choice models.
There´s also Eviews – unfortunately I have forgot most about it and only used it for a couple of easy regressions in my studies. Thus I just name it here. Same about GAUSS, which appears more mathematical than the rest of the pack. Recently I have heard about Octave, which is also more mathematical.
For my personal usage R is head and shoulders above anything else. Occasionally I pair it in Python or connect it to MySQL or PostgreSQL databases which also works well. R really helps you to learn statistics because you need to understand more in order to do something than you would need clicking your way through the likes of SPSS. Though if you need a GUI, you could try RKward or consider installing Komodo / Sciviews-R or Tinn-R on windows. The latter ones aren´t GUIs, but editors more or less that support Code Highlight and code suggestions which also help to go get it done.
Farnsworth Econometrics in R is a good read. Ah, and I can´t forget to mention the plotting. the ggplot2 package from Hadley Wickham is just off the hook. The best way to create graphics as long as you do not need them to be interactive. At the end of the day R is really to most flexible package: you can even install it on a webserver and build some nice webinterface – the sky is the limit.