Is there a better Windows Calculator?

Problem:
The prepackaged calculator on Windows (at least up to XP) is not very user-friendly

Answer:
This guy seems to have covered the issue pretty thoroughly, leaving you 3 options depending on your preference:
http://www.techsupportalert.com/best-free-calculator.htm

Also, although it would be ideal to find an OEM Windows app, their PowerCalc as part of their Powertoys pack seems too glitchy.