Cam UnZip was fairly easy to use, the interface is not as professional as WinZIP but pretty full featured - not my favorite freeware ZIP program but adequate for most ZIP-creation needs.

Although I find this type of ZIP program a little bit cluttered, CAM UnZIP seems pretty solid. No Spyware, no adware it's totally free (but donations are invited.) Strangely, I had the hardest time finding a link on their website to actually download the program. It's there on the left panel of their home-page, just keep searching (or click the link download link here. ;)

Free for Personal Use Free for Organizations No Adware/Spyware View Files before Unzipping Supports ZIP-64 (huge ZIPs) ZIP Context Command ZIP-to-Email Command Self-Extracting Archives Password Encryption Non-ZIP Formats Overall, I found CAMZip to be a fairly good ZIP program if you need a WinZIP replacement.
CAM Development Download CAM UnZIP (855k)

BigSpeed Zipper is one of those ZIP programs hard to easily quantify. Sure it's got the basic features and it's a little weak on some features I think are important... but then it has so many other features that I've never even thought of! I'm still trying to figure out the usefulness of some of them. For example, you can view the contents of a ZIP file online BEFORE downloading. Now that's kind of cool!

As far as interface goes, it's pretty non-standard but then sometimes a non-standard interface is the result of really cool features that would not fit into a normal interface. (Although usually, it's just because of bad design.) You go ahead and make up your own mind, its totally free.

Free for Personal Use Free for Organizations No Adware/Spyware View Files before Unzipping Supports ZIP-64 (huge ZIPs) ZIP Context Command ZIP-to-Email Command Self-Extracting Archives Password Encryption Non-ZIP Formats Overall, I was intrigued by BigSpeed's innovation and liked what I saw but the program is still a little bit clunky for regular ZIP work. I also want to see context menu commands!

BigSpeed Home Download BigSpeed ZIP (748k)

When I first read the specs on Optimal Archive, I was pretty excited. It reminded me of an old favorite of my "ZIPMagic" - which made ZIP files appear as if folders. Well, Optimal Archive has a lot of the same capabilities. It's a very powerful piece of software despite support for non-ZIP formats such as TAR ARJ and RAR. ;)

On the other hand, I'm not sure I would classify it as freeware. It's not that it installs noxious adware or spyware but rather it is itself an advertisement. Every time you use it you have to click through an advertising screen which gets old really fast.

Free for Personal Use Free for Organizations No Adware/Spyware View Files before Unzipping Supports ZIP-64 (huge ZIPs) ZIP Context Command ZIP-to-Email Command Self-Extracting Archives Password Encryption Non-ZIP Formats If it were not for the intrusive advertising, Optimal Archive would have been a great ZIP program. As it is, I don't think I'll be using Optimal despite its many fine features.
Optimal Access Inc. Download Optimal Archive (1670k)