Well you've covered most of the standards for Web. Nobody's going to ask you to write a web app in C. I'd say learn your databases, CSS and then maybe pick up Ruby and C# (in that order). Employers are typically looking for accomplishments, i.e. projects you've created or worked on rather than just a list of languages. If the job calls for a language you don't know, buy that language's reference manual, learn it, and then say you know it. Once you've picked up one language, other ones are usually just a matter of syntax.
The Systems Programming side of things is different, of course. I'm a mechanical engineer by training so as a consequence I know some embedded languages like Assembly for certain chips, Tcl, as well as C/C++ and a little bit of Fortran. If you stay on the web side it's unlikely you'll encounter these very often. My Javascript kung-fu is weak because I pretty much never do web stuff.
It's all about having a relevant portfolio of demonstrable skills.
The Systems Programming side of things is different, of course. I'm a mechanical engineer by training so as a consequence I know some embedded languages like Assembly for certain chips, Tcl, as well as C/C++ and a little bit of Fortran. If you stay on the web side it's unlikely you'll encounter these very often. My Javascript kung-fu is weak because I pretty much never do web stuff.
It's all about having a relevant portfolio of demonstrable skills.