Apple's TimeMachine. Has worked perfectly each time I needed to. Back up and running exactly where I last was, within less than 2 hours. And no manual intervention, just plug it, let it do its thing, done.
I back up with time machine too. I used it once when I had to send my macbook pro in for maintenance. I just hooked up my timemachine drive to my wife's macbook pro, and it worked great.