WinRAR iz da best they gives free updates...
WinRAR can Extract RAR, ZIP CAB, ARJ, LZH, TAR, GZIP, ACE, UUE, BZIP2, JAR, ISO, Z, 7-ZIP and other MIME-types
But WinZip can Extract only RAR, ZIP, CAB, TAR, GZIP, UUE, JAR, Z
Also WinRAR support both Zip and Rar Compress......