The unarchiver is a very useful utility for MacOSX [The unarchiver requires Mac OS X 10.3.9 or later] to meet your need with extracting file. This utility support zip, tar.gz, tar.bz2, rar, 7-zip, LhA, StuffIt and many other more file format.
The unarchiver is also a very simpe to install and use. Just get The unarchiver v1.6.1 from here, Unzip the file, and then simply copy it into your Applications folder or whereever you prefer, and then set archive filetypes to open using it.
After all finished then you can extract for example .rar files by just double click them. Simple, light, and very easy to use.