I have detected a certain powered USB hub feeding power back to my motherboard, causing me problems in booting. Now it seem to me that I will need some USB 3.0 power diodes to protect my motherboard against that. Using Schottky diodes leads to a 0.3V drop, which can cause problems in some loads...
So here is the shootout: an ideal diode circuitry. Specs: 5.5V, 2A.
My entry is the following:

Ignore the diode and the cap, as this is excerpt from one of my projects. The power comes in from top left and leaves top right, and the bottom rail is ground. Basically the same circuitry taken from the Raspberry Pi 2 schematics, but with some component selection changes.