Very good thread!!
Just to add to what's being discussed here... I think there is no such thing called "The Best Web Technology" simply because the whole meaning of Best Technology is a very relative term.. In other words whether a technology is best, better or worse totally depends on how and where its being applied. Most of the people point out one technology and say "that's no good" and most of the time its not good because it is not the suitable technology to apply for that particular scenario, not because the technology doesn't work or anything.
If we talk about PHP, PHP is undoubtedly the most used web technology on the web studies have shown that its being used by well over 19 million domains (that's a lot) and it seems this accounts for more than 30% of the web, so PHP has proven its capabilities. Main reasons for this would be that it does natively support the world most used Server - Apache Server and also the native support for MySQL, though MySQL is not quite the best DB around having these 3 technologies bonded together and offered for free makes WAMP and LAMP systems very popular. And newer trends such as PHP+Flash AS applications also supports the growth of the PHP environment. And not to mention that PHP is a community effort so support is available freely and if you are verse enough there's no need to wait for anyone, you yourself can expolore the PHP core!!!
.NET is also very powerful tool, but aimed at different target groups which are more of large companies which needs to cut down development time, as .NET development would be faster than generic PHP programming, (Having said that PHP couple up with IDEs such as Dreamweaver are as good as .NET now, if you've worked then you know what I mean) And the good thing is you can work with multiple languages in .NET but on the other hand development will only be feasible in Windows environment. And of cource its COSTLY!!
JAVA I think is the Jack of all trades, and it is everywhere weather standalone applications or web-based.
New technologies such as Ruby also coming up pretty fast... Infact I think in another 5 years time Ruby would make huge impact on the web with its framework called "Rails" (Normally the two known as Ruby on Rails) and IDE's like NetBeans already supports Ruby this will make it much faster.
So I'd say there not much of a difference between these technologies BUT it can make a huge difference on what grounds you are applying these technologies...
