My primary language is Perl. I've dabbled in php, c, c++ but Perl really is a 'swiss-army chainsaw'. I use it for small utilities, web apps, sysadmin scripts, etc. I do more system administration in perl than bash (although bash is a REALLY good 'language').
I'm involved in a handful of software projects right now in Perl, but when I finish those off I will begin learning Python as it seems that it is the next 'up-and-commer'.
Not intending to be insulting, but I've always viewed php as more of a toy than a programming language. I've never found anything that I could do with php that I couldn't do as well or better with a more established/complete language. In my experience, there's nothing you can't do with just Perl and C.
I have heard that php transfers better between *nix and windows than perl but I don't code for windows so it's not an issue for me.