ASAP-Utilities is a package of over 300 macros and scripts (commonly called 'utilities' by the creator) to automate common tasks and make difficult processes in Excel much more manageable.

Incredibly, this huge library of helpful additions are provided for free. There is a 110 page PDF file available for instructions on how to get the most out of the utilities provided, and there is even a blog in support of ASAP-Utilities and Excel in general.