If efficiency is to rule in boarding, I support the old United Shuttle 6-Zone system:
1. Window seats, rear of aircraft
2. Window seats, front of aircraft
3. Middle seats, rear of aircraft
4. Middle seats, front of aircraft.
5. Aisle seats, rear of aircraft.
6. Aisle seats, front of aircraft.
All Shuttle flights were boarded this way, so if you really wanted guaranteed bin space, all you had to do was accept a window seat.