It depends. CSS and JavaScript are core developer skills for AJAX web sites. PHP is a core developer skill for many web sites. Database skills can be meaning SQL programming, which is a core developer skill for many, especially in enterprise where you need to be able to sift through terabytes of data and billions of complexly interrelated records quickly.
I am a big fan of Apache Wicket, for developing Java-based web applications. Use standard HTML/CSS/Javascript for the front-end, and use Java for the “Code-Behind” logic, similar to ASP.NET. But there is no scripting in the markup, so it’s a clean separation of concerns.