Seeking good quality DVD ripping software for PPC G5, 10.4.11
Use the RipIt App. Choose the Compress option and within the Applications preferences you can specify the output file format. I have to say they made the process simple and worry free. I am using it on Snow Leopard so my experience may not be the same as yours.
You want HandBrake. Does everything the apps in the other answers do, bit it's open-source and free.
The latest builds have discarded PPC support, but the version before the current (0.9.5) build does have PPC builds available. You can grab those here (Version 0.9.4).
It Explicitly supports AppleTV.