I vote for Python. It comes with SQLite and can handle all other databases out there. If you pay just a little attention, then your code will run equally well on Windows, Mac OS/X and Linux. The site-packages contains almost everything that you could possibly need and there are many other excellent packages available. Increasingly Python is being used as the first language taught as part of computer science courses at most well regarded universities and there are many excellent books available.

If you are totally Windows focused, then IronPython will allow you to enjoy most of the Python advantages as well as giving you full access to .Net Framework. There also is Jython if you are more JVM inclined.

There are several web frameworks to choose from as well, Zope, Django, Plone, etc. And of course, you might want to check out Google AppEngine.

I prefer to use wxPython (wxWidgets) for GUI programming to maintain portability. But you could choose to use WinForms or WPF with IronPython.

With companies like Disney, NASA, Google, ILM using Python, you have to put it at the top of your list.

For more info: http://python.org/