In my personal opinion I think 7Zip is the best and the best part of it all is that it is FREE. I can extract pretty much everything you through at it and can create archives in various formats. It works on all windows, linux and unix platforms and here is the rundown of 7zip's features:
Find it here: http://www.7-zip.org/download.html
* High compression ratio in new 7z format with LZMA compression
* Supported 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.
* For ZIP and GZIP formats, 7-Zip provides a compression ratio that is 2-10 % better than the ratio provided by PKZip and WinZip
* Strong AES-256 encryption in 7z and ZIP formats
* Self-extracting capability for 7z format
* Integration with Windows Shell
* Powerful File Manager
* Powerful command line version
* Plugin for FAR Manager
* Localizations for 74 languages