Sneaky? We book window/Aisle all the time. We get an open middle about half the time. Otherwise, we often meet interesting people. We've been lucky and never had the 300 pounder or a smelly person in the middle.

If you don't want to risk separation, book that way anyhow. You can usually get someone to give up a middle and take the aisle or window. For us, a few hours of separation is no big deal as we mostly read or sleep on airplanes.