7zipit

7-Zip is a real good all-in-one compression/archiving tool.
Supports lots of formats:
* Packing / unpacking: 7z, ZIP, GZIP, BZIP2 and TAR
* Unpacking only: ARJ, CAB, CHM, CPIO, DEB, DMG, HFS, ISO, LZH, LZMA, MSI, NSIS, RAR, RPM, UDF, WIM, XAR and Z.

Get it here: http://www.7-zip.org/