Comment on BetterZip

Excellent application. First of all it may become a Mac version of WinRAR (thanks to supporting commandline RAR) and native support for creating 7ZIPs is excellent. Unlike Unarchiver it works fine with password-protected RARs and also lets you preview files before extracting. And finally, it works well as unarchiving tool even after expiration.
The best mac archiver I've seen so far.