I would second taking the center section with a family of 5. It's a little awkward and tight if you're packing in with strangers, but there's still plenty of room and it's fine if you know everyone in the section. The fifth person can sit across the aisle, where they will be facing the rest of the family (in this config, this is the pair of seats that most "sees" each other - you can't see the people directly in front of you).

Note that while those pictures above are correct for the seat type, none of them actually depict the plane you're flying on. I would also avoid 1AB if possible, as there have been multiple reports of autoblock issues causing people to get kicked out of the seats (to other seats in the cabin).