Backup Solutions for Mac OS X?

SpartanVII asks: "I purchased a Mac roughly two years ago and have made the switch with a fair amount of ease. However, one thing that has troubled me is how best to backup my important data to an external hard drive. Right now, I have rigged up an Automator workflow that runs every night, but I have also seen software options like SuperDuper and Knox. Since the Automator workflow lacks much of the flexibility and features available with these apps, I am ready to try something else. What app have you come across that provides the best backup solution?"