My favorite productivity tool, by far, for working in the typical office is Microsoft Outlook. Next favorite is whatever version of Visual Studio is available AFTER the clunky VS 2003.
Trying out the latest versions of Visual Studio Express at home, which includes a deep-dive into Windows Azure. Wow, things have changed around here since Visual Studio 2010! The NuGet package manager is pretty cool.
If I can’t deliver a task by the end of the day, I am finding more and more that this means I was mostly likely working on the wrong task.