STEPHENRS I've tried almost all of the other screen recording apps, and none of them even come close to ScreenFlow. Effortless UI and workflow, rock solid video recording/exporting, and many features not found in any of the other apps. It really is a joy to use. It costs a bit more than the others, but if you need to make professional quality screencasts, or want to be able to easily make adjustments after the initial capture, it's well worth the investment. The closest contender with regard to features and price is SnapZ Pro, and Screenflow blows it away...
(Version 1.2.1)