Here's my personal preference, based on the aircraft you provided. Mostly bulkhead seat, 39A, 39C, 39D, 39G, 40C, 40H, 40K, 59C & 59H.

My MOST desirable seats are 39A & 40K, both are Window seats. As both are in the bulkhead, there are extra legroom and yet you can 'walk' out of your seat(to restroom, breaks or stretching) without interfering your neighbors.

At 40C, as there is not seat in front but be aware of people stepping on your foot when the lights are off and when carts are moving during food service. As this seat is half facing the "door" to the front section(either Premium Economy or Business). Some may just walk straight without adjusting to the 'turn' to the Economy Class.

Row 71 is good for couple travelers who don't mind to be the last few to leave the aircraft as there are more room at the window side and yet enjoy the privacy.

All 777-300ER comes with USB and Power Port