I doubt if a master list would actually add something that http://search.cpan.org doesn't already provides. You would get a huge list, that eventually you had to dig through.

Now, if you want to know what module to use, if, for example, you want to do some form validation, you might as well search CPAN directly with "form validation". Besides that, CPAN also lists it's modules category-wise, so if you aren't sure what exactly you want to search for, that might help.