Comment Perl and Python both (Score 2) 67
Python and Perl make great data analysis tools.
They have a plethora libraries to handle things: Numpy/Scipy for Python and PDL/GSL for Perl.
They can access FORTRAN and C libraries as necessary for either performance or legacy needs.
THey are probably best because they are high level languages, very platform neutral, and cost signficantly less than other "serious" data analysis tools/languages.