I hesitate to give up my secret here because I love it so much, but my favorite Emirates A380 economy seat is 81K (I try to get it on JFK-DXB route regularly)- because it is behind an exit row but where the plane curves- leaving an empty space in front of the seat. There is lots of legroom and even enough space to get out to the aisle in front of your seat without having to disturb your neighbors. And in the window with space to lean. It's not near the bulkhead so limited baby-related noise (basinet seats are in bulkhead)
Downside is that it's sort of close to a serving area so can be a bit of noise- but worth the tradeoff I think and better than being near the bathroom.
I heard from an Emirates agent that 51K has the same set-up but haven't seen with my own eyes.