I voted Napoleon because there are a great deal of reforms he made that are still being used in modern-day France. That and I'm kinda biased towards him: I know he had his failings but I can't help but admire the man. It's also the last time France was the First World Power arguably: after that it was still among the Great Powers but no longer #1.
If I had to make a Top 5 of all the propsed ones, here is the one I'd give:
1. Napoleon I - For reasons already stated.
2. Philip II Augustus - The man who turned medieval France into a major power.
3. Louis XIV - The Sun King did a lot and he basically made France into the major power of the XVIIth Century
4. Charles V - Set the basis that would turn the tide in the Hundred Years War
5. Saint Louis IX - The great continuator of his grandfather's reforms. A very respected figure in his time also thanks to his piety and care for justice.
No love for Louis XIII, he did bring France back from the hundred years of civil war with the protestants.
I think he pays a bit too much the fact that he was a very distant man and a complex character. He also pays the fact of not having been as flamboyant as his father Henri IV and son Louis XIV. And then there is the fact his right-hand man was none other than Armand Jean Du Plessis de Richelieu, one of the most cunning and effective politicians France ever had, and a very romanesque characters. Add in Alexandre Dumas'
Three Musketeers where he is protrayed in a rather unfavorable light and you basically have the reason Louis XIII is probably the least well-known character among the Kings of France from the House of Bourbon.
Louis XI seems way overestimated since his so called "masterpiece" as a universal spider led to the formation of the Habsburg-Trastamara coalition that would encircle France for 2 centuries. So whatever were his skills, his action literally ended in a disaster for France.
To be fair, I think this should more be blamed on his successors than on the Spider King himself. Charles VIII especially since he's basically the one who threw everything out of the window: he rejected his marriage to Maximilian I's daughter despite the fact it would have brought back a good deal of Charles' the Bold inheritance into the realm (I admit his new wife allowed Britanny to become part of France but still) and is the one who started the mess known as the Italian Wars, just because he wanted Naples. That more than anything is why the Spanish and the Habsburg got closer.
Francis I probably was one of the worst kings of France. He just benefitted from good propaganda because he was a great arts sponsor.
Politically, Francis I wasn't the greatest admittedly. Still, he was a huge patron of the arts: it doesn't make up for all his mistakes but gotta give him credit for that. He's basically one of the reasons France has always been held as a bastion of culture.
Louis XIV also make critical mistakes (Versailles, the exacerbated cult of personality, revoking edict of Nantes, rejecting the Netherlands proposal to split Spanish Low countries between themselves, the Spanish succession could be settled differently, etc) but he also makes more good than harm (significantly expanding French borders, breaking the Hapsburgs surrounding, curbing the nobles, bringing stability the country, pushing France to its heights in terms of prestige and glory) . It was not his fault that his grandson and successor was so idiot. He also lived too long.
To be fair to Louis XIV, some of his mistakes can be explained by his personnality and his life. Him creating Versailles and his obsession with making the King the center of everything are directly linked to the trauma the Fronde left on him. The revocation of the Edict of Nantes happened at a time where he had become more religious (following the
Affaires des Poisons and his relationship to Mme de Maintenon) though it also followed a certain pre-existing logic (Louis XIII and Richelieu had curtailed the Protestant's power, this was one step further), his dealings with the Netherlands were linked to his personnal distaste of William III and the Spanish Succession War got the way it did because he was too proud of his family (though Carlos II's insanity and last minute will can also be blamed). As for the fact he lived too long, it's more the fact the end of his reign ended in bad luck: the smallpox epidemic that killed his sons, two of his grandsons and the eldest of his great grandsons and left only the future Louis XV as a successor to the throne, a boy of five at the time. Things would have turned out quite differently if there had been no smallpox to decimate Louis XIV's family.
I would also mention that Louis XV hismelf can partially be excused by his personnality: he saw most of his family die at a very young age and was always a bit of a loner. Add to that he was a bit depressive and suddenly you understand why he wasn't so great in the great scheme of things. At least he left us with a pretty strong French XVIIIth Century in the art department.
Personally,I think Louis XIV spent too much money on wars that yielded only a small amount of territory,as well as antagonizing a large part of Europe in doing so.
Louis XIV admitted on his deathbed that he had warred a bit too much. He even asked his great grandson not to repeat that mistake. You also have to remember that glory and demonstration of power was a huge deal in the XVIIth Century politics.