Good point about not being served at the same time, although you can work that to some extent simply by finishing each course in sync and of course asking the crew to try and accommodate.

I agree with Coffeemadman that the middle seats are the better choice as a couple I reckon. To me they strike a good balance between being able to interact enough while also allowing you to ignore each other when you want. It's hard to have a proper conversation over the meal as if at a restaurant, but you can certainly enjoy the 'how's yours' type thing. And watch films together, if you so please...