The party-list proportional representation system allows for most flexibility
The party-list system is a form of proportional representation in which people vote for a political party, rather than individual candidates. As this system is related to proportional representation, the political parties receive votes depending on the proportion of people who voted for them. The party-list system is also the most flexible system with three variants: the closed list, open list, and free list.  In the closed list, the political party pre-establishes a list of candidates that citizens can vote for. Instead of choosing individual candidates, the process is simplified as voters just choose a political party to vote for.  In the open list, voters can have preferences for candidates within a political party. Voters go beyond choosing a political party to select which specific candidates they would like to elect. In free lists, voters have the ability to elect candidates from any political party, as there are no pre-set lists for each party. Due to its ambiguity, the free list system is rarely used. The party-list system is the voting system that allows for the greatest room for flexibility and should therefore be used in elections.
The party-list system is incredibly susceptible to corruption and power imbalances. Wealthy individuals can sponsor a party and have a major say in the way the party functions. This is evident in the Philippines, where the president has deemed the party-list system as an “evil system.” The country’s political system is practically controlled by the wealthy sponsors of the political parties.