For me...

I use a tiered system to determine which platform to use for web projects:

HTML straight up unless you need dynamic features.  I am not a fan of high levels of dynamic fun on the client side... so I then differ to PHP in those cases.

PHP is fine for dynamic content, but I am not a fan of the platform for true web applications.  If you are writing a true application and using HTML to deliver content and take input instead of GTK or some other windowing lib, PHP is just not structure enough for the job.

My next tier is Ruby on Rails.  RoR is a full blown application framework, that just so happens to use the web to interact with the end user.  This is less about delivering news content for example and more about delivering and collecting info in a DB.  Rails is much better at these type deployments than PHP, but still lacks something in flexibility.

My platform of last resort is Java.  When you build a sight in Java you again have a full application environment, not just a web page.  When pulling out Java, you should be using a full waterfall development methodology.  Small projects in Java unless you are trying to learn Java are much more work than it needs to be.  But, the larger apps work quite nicely.

That is how I work... hopefully this makes some sense to you.  There are many tools out there and picking the right one for the job can make your life easier.  But the tool should be picked based on the job, not the other way around.

HTH
Kevin