php is great as a first language, and for portability/support. it has the benefit of being the most popular web language, and so most common web tasks are extremely well documented. but if you already know another language, i would learn anything but php. learning any other language will increase your skill as a programmer; learning php will accustom you to odd conventions and bad practices.
perl is also pretty great for cpan, but lacks the "hotness" factor. picking a popular language is an important part of finding relevant example code on the internet. you could write it in brainfuck, but where would you go with questions?