i like php for many reasons. but first let me say somethings about what i seen so far.
1st off java-based scripts are very slow in my 2 cents also you cant do as much.
2nd asp is a dying scripture, i have a host that always telling me that asp & asp.net will soon be like cobolt a forgotten language.
now that i got that out of the way
php is powerful, its very fast, and can run of just about any OS.
i also use it since its very popular and when i need help with it, i can find it.
but its mainly what you wabnt to program with, but i will always suggest php and all php people will, its just that way.
but look at this forum, look at the # of posts php has,perl,asp,asp,net,ect. php has the most in that section.
look at the overall availablity of scripts,tutorials, and other php items on this site compared to the rest.
and also php has a offical website that has an answer to everything you need. i do not know of any other web langage that provides a manuel that covers every single function, and feature add-ons.(if you have, plz provide a link of some kind)
but for future programmers, i suggest you look at what you want to do, want a chat room script, go java. anything else pretty much is your choice.
not to bang on java people but i only see java-based language (jsp,java) to be only useful for chat rooms, my 2 cents but i never seen any other good thing for it.
EDIT:
oh, btw i forgot to mention 1 thing that NO other web language does, show your errors on the page your testing. that is very handy to have when testing/debugging your programs, every other language pops a 505 error and you have to look through your error log(if you even have 1 or access to it) and that can really suck time and paients out of 1.