Best Polish Dynasty/Monarch?

Who do you think is the best post-1400 Polish dynasty/monarch and why?

Władysław II Jagiełło for the conversion of Lituania and a strong alliance of Poland with Lituanian, than resulted first in the defeat of the Teutonic Oder and second to the union in the Polish-Lituanian Commonwealth one century and half later.
 
If Stanisław August Poniatowski was given a fighting chance, I believe he would have been voted as the best.
He was a great patron of the arts and sciences he also supported many progressive reforms that could have seen the commonwealth really thrieve, sadly his hard efforts met with inernatal oppostion from Conservative member ans externally from Prussia, Russia and Austria, who were all interested in keeping the Commonwealth weak.
 
Casimir III is an obvious choice - the only Polish monarch called "the Great" in Polish historiography. He changed Poland from weak, backward country into a strong, well organized state, with good economy and modern infrastructure, a significant player in European politics. As Poles say "Zastał Polskę drewnianą, a zostawił murowaną" (When he ascended Poland was wooden, when he left us, it was from stone - it looses in translation).
Another of my favourites is first historical Polish monarch, Mieszko I. He introduced Poland to European world and culture, won first historical Polish battle (Battle of Cedynia) and conquered Silesia and Little Poland, defeating Bohemians rather by political than military manouvers.
I agree with Jonathan, that Stanisław August is seriously underestimated: he had to play against three powerful players, united against Poland, and his cards were very weak, and not by his fault. He achieved a lot, considering circumstances.
 
Casimir III is an obvious choice - the only Polish monarch called "the Great" in Polish historiography. He changed Poland from weak, backward country into a strong, well organized state, with good economy and modern infrastructure, a significant player in European politics. As Poles say "Zastał Polskę drewnianą, a zostawił murowaną" (When he ascended Poland was wooden, when he left us, it was from stone - it looses in translation).

A better alliterative translation into English would be:
"He found Poland built of wood, he left it built of stone."
Yes, Casimir III is a good choice.
 
Post 1400?
Kazimierz Jagiellończyk. He managed to regain Pomerellia (Royal Prussia) for Poland and he managed to retain autonomy for Lithuania and he managed to retain her wast territories. He placed his descendants on thrones of Bohemia and Hungary. He elevated house of Jagiellon to the level of greatest houses in Europe - quite an accomplishments for son of former pagan.
During his reign the culture in Poland also flourished and his reign was a period of transition from medieval to renaissance in Poland and Lituania.
 

Redhand

Banned
August II may not have been all that great but he deserves props for his fertility prowess. Having over 350 children means that you have racked up a really impressive Jeter-esque blackbook. ;)

More seriously though, Jan Sobieski was in addition to being a great soldier was actually a talented ruler and knew the right diplomatic moves to make, keeping Poland with a legitimate chance of survival even after the disasters of the Deluge.
 
Sigismund II Augustus.
He was tolerant (and it was a good basis for a strong country with different faiths), he controlled the country, he ordered to create the Second Statute of Lithuania, and he created "Republic of the Two Nations".
 
Top