I would like to see an option added to the 'Software Packages' module to purge configuration files on package removal.
Ticking the option would just put '--purge' to or replaces 'remove' in the apt-get command:
apt-get remove --purge* <package-name>
apt-get purge* <package-name>
There is also a purge option available for aptitude.
That's an excellent suggestion - I will add an option when deleting a package to also purge it in the next Webmin release.