A number of my (ahem) file sharing enthisiast friends tend to favour the RAR compression format over ZIP, since the “word on the street” is that it makes for smaller files. This is particularly handy for all sorts of uses, from creating archives of version-control repositories of your code to say, passing around copies of the leaked Arcade Fire album, Neon Bible.
Jeff Atwood, author of the “you must read this if you code” blog Coding Horror, has gone beyond accepting the prevailing wisdom and done the legwork. He took the data from a page benchmarking a large number of file compression tools, fed the data into Excel and produced some charts which make it easier to interpret. The practical upshot of all this is that your best bang-for-the-buck compression tools in terms of output size (smaller is better) and speed (faster is better) are WinRAR and SBC (which neither he nor I had heard of before). He writes:
RAR offers a nearly perfect blend of compression efficiency and speed across all modern compression formats. And WinRAR is an exemplary GUI implementation of RAR. It’s almost a no-brainer. Except in cases where backwards compatibility trumps all other concerns, we should abandon the archaic ZIP format– and switch to the power and flexibility of WinRAR.
(Before you start complaining that recipients won’t be able to uncompress RAR files: you can create self-extracting RAR file for Windows with a sub-100K overhead, StuffIt Expander does just fine uncompressing them on the Mac, and if you’re on Linux, you should have the chops to locate the RAR unarchiver for your particular distro.)