Universal Extractor

http://www.legroom.net/software/uniextract
Universal Extractor is a program designed to decompress and extract files from any type of archive or installer, such as ZIP or RAR files, self-extracting EXE files, application installers, etc.  The full list of supported formats can be found in the table below.  It's able to support so many varied file formats by utilizing the many backend utilities listed in the credits at the bottom of the page.
Please note that Universal Extractor is not intended to be a general purpose archiving program.  It cannot (and never will) create archives, and therefore cannot fully replace archivers such as 7-Zip or WinRAR.  What it will do, however, is allow you to extract files from virtually any type of archive, regardless of source, file format, compression method, etc.
The original motivation behind this project was to create an easy, convenient way to extract files from various types of installation packages without the need to remember arcane command line switches or track down separate utilities to handle the unpacking.  Over time, and with the encouragement of its many users and the fine folks over on the MSFN forum, it has evolved into a mature and very capable unarchiving utility that many, including myself, find indispensable.