How about a law that allows players to vote on what sort of voting system their nation uses. For example some options could be:
First Past the Post
Proportional Representation
Electoral College
German Style Proportional Representation (a different name would be needed for this option)
Obviously it would be a constitutional change so would require 2/3 of a legislature to support it. I'd love to hear your thoughts/opinions and any other ideas you have for other voting systems ext..