Who was the most successful ruler in history?

Genghis Khan.
Legacy is still around today-
"
~10% of the men who reside within the borders of the Mongol Empire as it was at the death of Genghis Khan may carry his Y chromosome, and so ~0.5% of men in the world, about 16 million individuals alive today, do so.
"

http://blogs.discovermagazine.com/gnxp/2010/08/1-in-200-men-direct-descendants-of-genghis-khan/

Very advanced Kingdom, nearly unstoppable.

Sorry but I dont believe that as the Mongols didn`t have any kind of legacy in the same way the Greeks or Romans did.Sure,they were good at militarily conquering nations,but they did not have any thriving culture of their own.

John F. Kennedy , The space race was awesome.

I too thought about John F Kennedy because of the Space Race and what he did for racial equality in America but he was only president for 3 years

Darth Vader.

I agree, while I can assess that he probably wasn't the most " successful" leader, his work has made a profound impact on a lot of people including myself. So I threw his name in for good measure, It just a shame his presidency was unfortunately ummm cut short?

Ok,if the factor was long term legacy,who would you pick ?

She was very good at the crucial moment, when the Armada came in and domestically she tried to calm down the fervent religious in-fighting that was the norm in that period. However, I don't think she really did a lot beyond that, she mainly concentrated on killing perceived enemies (a bit less than her predecessors, but she was still quite the murderer), applying toxic chemicals to her skin and tormenting her female relatives.

That's Daenerys Stormborn of the House Targaryen. The first of her name, the Unburnt, Queen of Meereen, Queen of the Andals and the Rhoynar and the First Men, Khaleesi of the Great Grass Sea, Breaker of Chains and Mother of Dragons, to you.

That's still hard though because it doesn't necessarily make someone a good ruler. Henry VIII is probably the most famous of all English monarchs and his legacy on the country's religion is still visible, yet he wasn't a particularly successful ruler.

Sorry but I dont believe that as the Mongols didn`t have any kind of legacy in the same way the Greeks or Romans did.Sure,they were good at militarily conquering nations,but they did not have any thriving culture of their own.

This legend tbh... Look at him, does it look like this man could do anything wrong?

Enforcing your genetic legacy as the Mongols did is so much more impressive than what the Greeks did, if the Greeks didn't make the discoveries they did, someone else would have done that, it means very little.

I agree, though the defeat of the Spanish Armada was mostly based on luck rather than pure military prowess.

Elizabeth I