Which war was more significant historically: the Napoleonic Wars or the War of 1812?

Definitely the Napoleonic Wars. There was a good chance that Britain might lose the war against Napoleon. There was little chance that Britain and her Canadian lackeys might have defeated the Americans. Even with the capital burnt and in ruins, the Americans would have showed the same result they did during the Revolution. Britain would never and could never have subjugated the Americans and they knew it, their goal was to inflict decisive damage and to play to the strengths that were denied them in the last conflict - namely using their fleet. They did so and it's what led to their successes. The Americans knew that the British hadn't gotten any better at soldiering since the last time, and it's unlikely that people in Britain would have been willing to invest the time, manpower, money and effort in another prolonged conflict to try and rein in a people who were overwhelmingly and blatantly against Britain.

The Napoleonic Wars. The War of 1812 was a provincial sideshow in comparison.

The Napoleonic Wars created the political geography that resulted in the shape of Europe and the two World Wars. Outside Canada and the US the War of 1812 was no more than a large skirmish.

The Napoleonic wars (1798-1814) were world wars, world wide and 10+ times bigger/ more important than the short 2 year war of 1812.

it depends where you live 1812 is not high on the list in Europe ,The Napoleonic were very important they covered most of Europe and Russia too as far as N Africa that is a huge part of the world North America is big but not that big and the revolutionaries were always going to lose they could never take Canada and were extremely impertinent for trying