I have to go with "Power Simplified"
I was reading the posts and came up with it as I read.. then I found that someone else had posted the exact quote! Two Apple loves can't be wrong.
It really is the best solution, it hints about the Unix underpaintings of the OS, and the Aqua interface...
Another one that stuck out was "Love Your Computer Again" which would fit very well with Apple's Hippie image.
Apple only wins this war if they can prove that there really is no choice in computers... using a PC is just wrong...
How about some of these for consideration:
"Apple, it's just right"
kind of a clarification to the PC users out there.
"People and Power holding hands"
Kind of long, but could be used on an independece political freedom spin.
"Are you there yet?"
This one could be turned around a bit too easily... critics of the mac could ask the question back... but I figured I'd leave it in as an option.
"Smile, it's a Mac"
Just a playful reminder to those considering the mess of buying a machine... and it also serves the people who currently own the machine.
I am sure there are more, but those are just off the top of my head.