The Mathematica showcase on Code Golf[1] is by far the most impressive showcase of any language I've ever seen. (Start reading from the bottom.)
There's something really, really powerful about good interactive tools and learning math. I'm convinced my success in subjects like calculus and diff. eq. were driven by toying with programs like Mathematica.
Anyway, I still find myself reaching for it occasionally. I recently used Mathematica for some FFXIV raid group statistics. Once you get accustomed to it, it's incredible how productive you can be at solving specific problems. "Nuclear reactor included" is a great turn of phrase (from above).