Ok ya, you can beat France, but only a actual player can unless the French AI gets screwed over by strange circumstances and cataclysmic events. French lands are stupid rich, they have spectacular ideas, western tech, and an amazing location that allows expansion into both the iberean and Germany. Who cares about german coalitions when you can drown them in doomstacks of 35 in the 1470s. Also, lets say that all of europs allies against you, you just go colonizing until the french revolution, then drown them in revolutionary soldiers, a strategy I had too much fun with.
Fun fact, a consolidated iberea is still weaker than a consolidated France. Not by much, but still weaker. Now if spain also get's naples, then things are a bit more even but not much.
But I wouldn't recommend France to a first timer, it is too faceroll and can make you overconfident.
My top 10:
1: England: AI's can't touch you in your fortress of solitude. Make a navy then this honeybadger dont care. Not the most fun, but easy.
2. Spain. Really hard to have a Spain playthrough go horrifically wrong. Worst comes to worst you dominate the new world.
3: Timirids. Providing you release persia as a vassal to prevent revolts. Super easy domination of india.
4: Ethiopia. Location location location. Great ideas and the mamluks never seem to really bother you. Worst comes to worse they die in the dessert.
5: Manchu (any jurchen tribe). Long live the qing baby. I love their ideas and they just roll over ming to get some spectacular provinces. Looting is op too.
6. Muscovy. Location location location. Worst comes to worst watch your enemies freeze in the winter.
7. Denmark. Similar to engand except muscovy can be an arse sometimes.
8. Austria. Isn't higher on the list because France is a butt.
9. Teutonic Order. Provided you get a start where poland does not pu lithuania. Has a pretty good chance of happening in 1.8.
10. Portugal. Exactly the same as england except with less land and you need to keep castile happy.
My list may seem like it's missing some people but I have yet to finish a game with many of the strongest nations, and I only list nations I have finished a game with. Finishing a game is about 300 years of gameplay to me.