Wonderful topic Gary.
I'm a devout Excel user. Most people are unaware of the powers of this program. It really can do some wonderful things. The simple, easy to use interface makes learning it a breeze. I started using it when I worked for CIBC, where I realized what a great tool it is. From there I used for a variety of statistical purposes including lots Fantasy Sports spreadsheets.
What I like the most about Excel, is that it doesn't give you so much rope that you end up hanging yourself. I see that as a problem with Matlab.
Granted Matlab is a much more powerful tool, but if a really need that much power I use
Maple. Maple is a beautiful piece of software, that covers all my symbolic computing needs. From solving DEs to telling you what 27,343rd prime number is, Maple does it all. (I may be a little biased, I had a 4 month internship in 2002 doing Maple research at the University of Western Ontario)