DEfinitely A/B. Three reasons:

a) near a window
b) E/F you are both trapped and have to climb over strangers to get out
and more interestingly
c) some people, like Ms Raffles, REALLY hate flying backwards. The E/F seats both face backwards so you are stuck. If one of you starts feeling a bit odd (like sitting the wrong way on a train) so can swap with the other if you have A/B.