That's a near impossible question to answer with just one choice. Each of those choice has advantages and disadvantages. It's more about picking the right hammer for the right job.
I voted for PHP. It's open source, there is a very active development community for it, it's easy to learn, and its a very capable language.
.Net isnt a language but a framework PHP will win the vote by a long way even though most in the know will not say that it is the best. Why does the fact that you can read the source code of the language/ framework itself make it better than others? Surely the availability of open source sites/ tutorials/ forums etc is much more important than being able to see how the echo command is actually interprited? Naturally voted for .Net as it is the best by some way but will have to see how much of an improvement PHP 6 is, it will certainly narrow the gap.
I voted PHP, but not necessarily because it's the best - I don't have enough experience with the others to judge. I stick with what I know
PHP is great for pure websites development and presentation. Any back end support thats required I'd pick Java for it.
C# is completely object oriented, and lets you take over the full capibilities of the server. You can easily create custom graphics with pens and fonts and all the nice GDI+ goodies, then stream the results down to the client as a jpeg. And you can spawn threads to do your instrumentation in a fire-and-forget manner. It really comes down to the skills of the developer more than the language in most cases. But we all have our preferences, and that's mine.
.net is not a language. but i am going to say C#, i think its have the best design of all the languages listed. its alot like java but it just more developer friendly. pros: sexy providers; sexy xml support; sexy data controls; sexy tools to gen data tables. sexy data types sexy web services support. cons: not platform independent if(itisSexy) { itIS = "c#"; { else { itIS = nasty; // nasty=php }
Lately I've been getting more into PHP, as it's easier to find quality *NIX web hosts, and look at the difference in coding: ASP vs PHP - reading from a text file
Been reading more and more into Ruby lately and where it can go is quite impressive. I asked myself when PHP would go 'out of style' yesterday and couldn't come up with a when for the thought. Any estimates?