If you take a window aisle seat then it doesn't matter if the people in the other seats know each other or not - they have to get past you to get out of the seats.

The Middle aisle seats - especially 3 seats have a good chance of the other two seats being occupied by people who know each other and hence they won't bother you to get out.

Of course if it's a 4 seat middle you run the risk of a couple with small child