You will never find document saying and proving that "PHP is clearly better" or "ASP is clearly better".
Personally, I would never choose a development environment with such close ties to one single platform (Windows+IIS). ASP is available on some unix-platforms, but for ASP to be really fun, you'll quickly need Windows-software to supplement it.
Generally, I assume that the answer to your question will vary: If you ask here, most people will say that PHP is best. If you ask in an ASP discussion group, then people will probably tell you that ASP is the best. And so on...:
Maybe it's really JSP which is best - once Java matures enough to live up to the old "write once - run anyware" hype... ;-)
