Inspired by the thread asking a similar question about the Teutonic Knights still ruling what later became Prussia, I propose this question: what would the world be like if the Knights of Malta still ruled Malta? This is a very interesting question if for no other reason than the fact that the POD can be as late as 1800.
By late 18th century the wast majority of the Knights budget came from either property in France or the French nobility - both sources of income that the revolution stopped.
A Knights of Malta that weren't invaded by Napoleon or the British would be very poor, with bad relation to the "ordinary" maltesians and sitting on a valuable island that many wants to have and they can't defend very well. That would lead to big changes during the first years after 1800.
To survive until today the Knights would have to ally with someone, thereby solving both money and military problems. They would also have to involve the non-knight maltesians in the government and modernize fast. Renting a fleet base to the British? Raising mercenary regiments for the British? Aiming to become a new Hong Kong?
The world wouldn't be very different - Malta is a small island. The result could be a slightly more "exotic" world with not only Gurkha soldiers and French Foreign Legion, but also a militant knight order.
Malta could also turn out to become the North Korea of Europe, run by bitter aristocrats that fled Europe during late 19th century, treating maltesians as serfs.