If you're not a big fan of StuffIt and want an archiver that can handle just about anything then Springy is a simple to use, yet powerful archiving and compression utility for Macs.
Springy integrates with Finder to make archiving as simple as drag and drop or through Springy’s Finder contextual menu. One thing I really like is that you can preview and browse archives before extracting them - very useful if you're dealing with big archives.
Extracting and compression is extremely quick and you can modify files within an archive just by double clicking.
Most major formats are supported including: ZIP, TAR, RAR, 7Z, PAX, CPIO, CPGZ, GZIP, BZIP2, UNIX Compress, SIT, JAR, DMG and ISO disk images.
Note that as an added bonus, you can also create disk images with it as well. The only problem I had was with the initial installation. Springy advises you to drag the Springy application to a Contextual Menu Items folder.
However, every time I did this, it just opened my downloads folder instead.
Springy is a powerful and easily accessible archiver that will be a breathe of fresh air to those tired of StuffIt.