On a plane, the best headphones aren't the ones with the best sound. They're the ones whose battery outlasts the flight, that plug into the seatback screen, and that you can doze off in. For long flights from Canada, over-ear noise cancelling with 24+ hours of battery wins.
The over-ear picks
The Sony WH-1000XM6 is our pick for most people. Sony quotes up to 30 hours with noise cancelling on, which is Toronto to Manila with battery to spare. It comes with a cable and a 3.5 mm input, so it plugs straight into the seatback screen, and it's light for over-ears, which matters when you're sleeping sitting up.
If comfort is the priority, the Bose QuietComfort Ultra (2nd gen) is the other strong choice. Bose also quotes up to 30 hours (23 with its immersive audio mode on), and it folds flat to fit a smaller space in your personal item.
Side sleepers: get earbuds
Over-ears and a window-seat lean don't mix. AirPods Pro 3 get about 8 hours per charge with noise cancelling (up from 6 on the Pro 2) and 24 with the case, so you can top them up during a meal service.
The seatback screen problem
Most seatback screens still use a headphone jack, not Bluetooth. Over-ears with a cable work straight away. Earbuds need a Bluetooth transmitter for planes: it plugs into the jack, and the AirFly Pro 2 connects two sets at once, so two people can watch the same film. A few older planes still have two-pin sockets, so a metal two-prong airline adapter is worth keeping in the case. Skip the plastic ones; they snap.
Getting the most from them
Turn noise cancelling on before take-off, when the engines are loudest; you'll still hear the safety briefing. Keep a cable in your personal item in case the battery dies mid-flight. And know the limits: noise cancelling won't help with ear pain on descent, so swallow or yawn as the plane comes down.