While I don't find the "best" and "worst" categorisation to be pertinent for a number of reason, and do not believe in ultra-personnalisation around the figure of the king (even for a king like Louis XIV this can be stated, read Louis XIV et vingt millions de Français [Louis XIV and Twenty Million Frenchmen] by Pierre Goubert if you have any doubts), on Louis XVI you should nuance the capacity of rising up and overthrowing. There was a deconsecration of the figure of the king during the Revolution, and a transfer of sovereignty from the king to the people through the Assemblée nationale, but the English example with the execution of Charles I was an example the king knew of. Furthermore, Louis XVI himself made the conscious choice of committing high treason, the start of the Revolution was actually characterised by sympathy towards the king, with the old myth of bad counsellors at Versailles. So he himself burnt that sympathy and created the Republic by his policies, excluding the possibility of a constitutional monarchy, which was what the patriots initially demanded. That being said, I agree with Charles X having been an awful king by all measures, being particularly out of touch with his ultra-royalist reactionary approach.