Which (software)graphing calculator do you use?

It depends on what I'm doing. I like matlab cause it's so feature rich. If I need to do something simpler I use excel.

For linear algebra stuff I use Matlab at school and Octave at home.

For crunching numbers, etc., I will use either Windows PowerToys Calculator or my classic TI-85.

Originally Posted by tabstop

There's always gnuplot, of course, but it doesn't have the tools that people expect of graphing calculators (finding intersection points, and the like).

Seconded. And don't underestimate gnuplot -- it can do what you want, it's just not completely straightforward. To find intersections between two curves, subtract one from the other and solve for the zero point.

As far as straight graphing, it works fine.