- Matlab! It makes life so easy. (that or one of the other mathematical packages that are around the place, excel included).
- Paint, though I could live without it I suppose, but most or my report graph ... enhancements are done on Paint ...
- some kind of media player,
- Cool Edit pro (though I haven't used it in a while).
- VLC player!
There are more, I'm sure, but these are the ones that first come to mind.