There is a wiki that is trying to keep a list of favourite modules and why. My Favourite CPAN Modules
I like the idea but the format and information currently leave a lot to be desired. But if you want reviews of modules it is a start. I think a community like Perl Monks is better than a static list. Because most of the times a search for a particular way of doing things ie a module, involve defining the problem you are trying to solve. And most of the time your problem is not unique it is your perspective on the problem that is. And through discussion you can usually find a solution or improve your perspective on the problem. And having both tools availbe is of course ideal. But as others have said CPAN by category is the best bet to go or state your problem here and just chat about it.