What would you say is the best CGI editor?
I don't know about best, but I've used Open Perl ( http://open-perl-ide.sourceforge.net/ ) and been happy with it.
Here is a list of good editors. http://www.perldoc.com/perl5.8.0/pod/perlfaq3.html#Is-there-an-IDE-or-Windows-Perl-Editor-
I find Komodo to be, by far, the most useful. However, it is not free and can be a memory hog. Open Perl IDE would be my next choice (if you're looking for a free editor then it is the first choice).