GUI zip utility for Mac OS X that supports previewing

Zipeg is free. It allows you to view the file hierarchy without extracting any files. It automatically extracts all of the files in the currently viewed directory when that folder is opened, including the archive's root directory. This means that opening an archive and viewing different directories in it are expensive processes. It deletes these files when the viewed folder is changed or the archive is closed. It uses these temporary files to provide previews. It does not support creation of archives.

BetterZip is $20, and people seem to love it. I don't think it's that good. It seems to support Previews by just extracting the entire archive to a temporary folder, but it does have a built-in preview pane that seems to support more than Preview.app does.

This might help you out. It's a Quicklook plugin called BetterZip that allows you to view the contents of an archive by simply tapping space. It can preview the following archive formats: ZIP, TAR, GZip, BZip2, ARJ, LZH, ISO, CHM, CAB, CPIO, RAR, 7-Zip, DEB, RPM, StuffIt’s SIT, DiskDoubler, BinHex, and MacBinary.

The partial extract part unfortunately does not work, though. This is only good for previewing.

Pacifist is a shareware app that lets you use the spacebar preview functyion (whatever it's called). It also lets you do partial extracvtions and works with .dmg .zip, .tar, .tar.gz, .tar.bz2, and .xar archives, but not 7z apparently. It has a trial mode, it just makes you wait before showing you the contents of the archive.