If you fly enough, you’ll develop some strong preferences: aisle or window, Airbus 320 vs 747, even which side of the plane you’ll be on (hint: in warmer climes, the sunny side of the plane can get crazy hot as it’s sitting at the gate).
Seat Guru can help. Listed there, by airline, and then by airplane type, is pretty much everything you need to know. Which window seats don’t actually have a window? Which seats don’t recline all the way? Where is the loo? All answered on their color coded charts.
Occasionally these charts are not fully up to date, as airlines change the configuration of seats whenever they can figure out a way to squeeze a few more in there, but overall it’s a great way to at least up the chances that you’ll get a good seat.
As someone who has more than once sat in the incredibly loud, no recline hell of the last rows, that truly is something to appreciate.