I'm a window fiend and the wings are my enemies. If I can't sit in front of the wings, I'd rather go very near the back to avoid wing-obscured views or heat haze from the engines. The back riow is good for avoiding seat kickers and child noise - children's mouth's usually (but not always) point forwards.

Also, on a recent BA 747 flight with a friend, we specifically wanted the back three rows as they have pair seats at the windows.

Obviously, I'd usually rather fly in a higher class of cabin if the opportunity arose.