If you often receive zipped, or otherwise compressed files, you'll know an extraction application is necessary. WinZip is probably the standard for PC users, but now StuffIt Expander, the long time Mac equivalent has come to Windows.
This free version only handles expansion - you can't compress your files - but unlike WinZip, StuffIt Expander will unpack many different compression formats. This includes common ones like RAR and TAR files. That alone makes it quite an improvement over the competition.
Expansion is unproblematic, and the simple interface has buttons to expand single files or groups. Destination folders can be chosen as you would expect, and that really is about it. There are no compression tools in StuffIt Expander, although they are available if you upgrade to the deluxe version.
Due to its speed, simplicity and broad compatibility, if extracting and expanding files is something you do a lot StuffIt Expander is a great solution