YemuZip is a simple, no-frills, easy-to-use application for making ZIP files. Unlike the built-in compress function, YemuZip lets you choose between preserving Mac specific metadata and making clean PC-friendly ZIP files. YemuZip also includes convenience like the ability to zip straight into a new email.

Note: The free version is now ad-supported. An ad-free version can be bought from the Mac App Store using the 'Buy' link above.