(preface: I am not a shill, but I guess all shills start by saying that they are not a shill) I find that version 12 of the Stuffit Suite is excellent. Stuffit Expander always works for me, unless the file is damaged. Also, it decompresses many formats, such as sitx and sit (obviously), zip, bz2, unix Z, gzip, rar, hqx, uu, etc. etc. etc. Before I knew what that RAR is, I received a file and did not know what to do other than drop it onto Stuffit Expander. It opened like a charm. Yes, I could have downloaded a RAR extractor, but I was completely befuddled and needed the file opened right away. Sometimes in email attachments I get weird MIME types with non-descriptive file extensions or even no extension at all. What am I to do with those? I drop them on Stuffit Expander and it figures out what it is and opens it.

Let me note a few things that stick out about the Stuffit Compression tools (DropStuff):
Damned good compression ratios. It might be slower than zip, but it is the best game in town. It uses different algorithms for different content such as PDF, jpeg, text, what have you. If you are compressing, why not use the best? Simple example--take a 290 MB text file uncompressed. Use the best zip method in GNU zip (91 MB) or Apple Finder zip (93 MB). Using the best compression in Stuffit, the file is 67 MB. AS WITH ALL COMPRESSION, YOUR MILEAGE MAY VARY. But I find this to be fairly typical. It is works well also for folders that contain different kinds of data, some text, some binary, some pictures, some PDFs

Another perk of Stuffit is that you can select different amounts of error correction. You can choose between 1% to 33% overhead to get increasing levels of data integrity. Are you paranoid? Use 33%. Using the example above, you will have around the same size file as the zip, but with absurd protection. Have you ever had a large archive that you can't open because of an error? I have, and I nearly s*** my pants because I could not open the file. This seems to be true archival quality. If you drag files around to different computers for years and years, you will run into a problem sometime. Don't believe me? Then why do RAR and PAR2 formats exist? (Learn more at wikipedia.org). There are times when I have lost data in zip/tar.gz that I would give $100 to get it back. Even $500. All because of a speck of dust or an aging hard disk.

Ever notice that computer chips are not getting much faster? Intel et al. usually add more cores. I have an 8-core mac, and Stuffit uses up to 650% of 800% when it is compressing. GNU zip and Apple Finder zip use 1 thread. Stuffit may be slower, but it is (*usually*) better, and the programmers are trying to do things to take advantage of the multiple-core reality. This somewhat ameliorates the speed difference and actually makes things faster if nothing else is going on on the computer.

Sensitive data? Use Stuffit's 512-bit encryption model. I think that you can get this kind of protection with other software, but only 512-bit if you use another encryption package. Then, get your colleagues to also install the decryption utility. Yeah right. (I admit that I do not usually do encryption. But it is there if I need it.)

DropStuff does not force you to use the proprietary .sitx format. It also has absurdly good compression levels for zip, tar.gz, tar.bz2, and tar.Z. Changing between them is a click away.

Does one click bother you? Fine, use Stuffit's command line tool called "stuff". I use it all the time in scripts that I write. And all of the Stuffit goodies are available in the command line version.

Just to comment on one of the biggest criticisms of Stuffit. You have to enter your email address before downloading the Expander. Then, the company will send you an email with the download location. And, surprise surprise, you will find that you are on the Stuffit email list, and they will "pester" you to upgrade to the version that lets you also compress data. PLEASE KNOW THAT IT IS TRIVIAL TO GET OFF THE LIST. Just click the "unsubscribe" that is at the bottom of every email. Or add them to your Spam blocker. Or buy the software for $100. Whatever. You get something good for essentially nothing. Have you ever bought from Apple? Adobe? Microsoft? Hehehe, versiontracker? You want to talk about spam...... I think that it is misguided to single out one company for doing what every company does.

Anyway, I guess I conclude by saying if you want all the features of Stuffit (which I, and probably you, really do) then go for it. If you can find a free, and better solution, then please reply and let me know what that software is. But I like the Stuffit suite, and I wish others would use it because it is actually quite nice. It is also cross-platform (not only mac like many of these comments say) and I think that it competes favorably with WinZip nagware.