I like windows because I can see things. Windows are also the best for sleeping as people don't climb over you.
If it is a daytme flight and I know I am going to be restless I book an aisle so it is easier to move around.
Other than that, considerations are:
Are you bothered by kids? (don't book something near bassinets)
Are you bothered by people moving about? (don't book near loos or galley, or aisle).
Do you need a certain number of seats together as a couple or family?