PHP is easy to learn, however really hard to master. Reason is simple: there is a lot of freedom in this technology, which explains why beginners feel at ease with it, but also explains why PHP projects often goes messy.
As already said, there's no best web technology. There could be a best pick in your case depending on parameters like:
Which architecture will you be working with?
For example if you're going to interact with Minecraft/Sponge, a Java web server could be a nice choice.
Which technology has good docs/community? Or which would be easy to learn by fellow developers? PHP Frameworks (symfony, yii...), nodejs fullstack frameworks (meanjs, meteor, mojito)
What do you already know?
Capitalize as much as possible on what you already know, and like.
Will you need to work with mobile devices?
Web apps now are often meant to be used by mobile devices. Some frameworks may be more friendly to it
Do you want to be modern, cutting-edge?
As you can see possibilities really are numerous. In my case, I started long ago with pure PHP, then PHP frameworks. I got bored by it by seeing new technologies but I keep a special place for PHP because many servers with only FTP access are PHP-ready. Then I worked with heavy Java apps. With these, you should be able to do powerful and flexible things but with really heavy coding structure.
I would just not recommend learning a language + a framework. That would be too much for you and for possible collaborators. That said, up to you!