Python, CPython in particular. I use it for everything, save fast stuff and embedded programming. It is faster than PHP, has an elegant web framework - Django - doesn't break compatiblity often(YMMV) and is IMO more logical than PHP, also has great introspection.
Isn't as fast as C++ or even Java, but works are to make it faster.
I can't believe no one has said AS3 (although, i think its a scripting language, but then isnt Java?)
Its getting a built-in 3d engine soon, its got sockets, and lots of built-in classes and functions which are internal for better performance. Plus its more popular among web users (something like 98.7% penetration)
Biggest downside its that its.. not.. free. Gotta say its kinda worth it though.