I like Perl the best and javascript+ruby the least.
Maybe I'm missing something about Perl?
You better follow the best practices for Perl and it is like the other scripting languages. Check the Modern Perl book.
My reason to prefer Perl is because it is fun and the culture is good. The business case for Perl is CPAN. E.g., check Moose and additions like http://search.cpan.org/~flora/MooseX-Declare-0.35/lib/MooseX...
Maybe I'm missing something about Perl?