This *is* an old and ongoing debate, but now that I've been developing Web sites and applications for 15 years I don't really think it matters what language you use (I obviously prefer Perl).

The typical argument against Perl is that it's old and funky. Personally I don't believe that. Yes, there are the languages de jour, like Ruby on Rails and the various Python-based frameworks, but unless your trying to impress people at a cocktail party, it's the classics, like Perl, that stand the test of time.

All that said, I could go with any of them (if I knew them well) as long as:

1. the client side of the application is friendly and intuitive
2. you can sleep at night knowing that what is behind the user interface is lovely, tight, secure, clean, readable, extensible, best-practice code that can be easily maintained by another
3. you can find others people who know the language and can assist you on the big projects