What a ridiculous scenario! I mean, to even begin to conceive of it, you would have to assume that the Emperor's military genius became clouded by arrogance, laziness, and some loss of energy in middle age... and we know those things could never happen!
But assuming he was beaten in 1814 or 1815, then the Napoleonic Union would never have come into being. Britain would have gone on to become the world's great industrial and trading power, perhaps for decades, instead of sinking into second rate status. Europe, with its single currency, closed markets, and uncompetitive industries, wouldn't have stagnated into an economic backwater either.
The United States might have had to wait until sometime in the 20th Century to become the world's leading economic power, instead of achieving this position after the Civil War, as it actually did.
What if Napoleon was defeated by the Coalitions?It is plausible, considering that almost every country in Europe was opposed to him. I read a good TL by Zach about precisely the subject

what if?