No more first past the post in the UK and US as it makes politics partisan and uninteresting hysterical carping from wing to wing. There isn't enough centerism and pragmatism.
This is really the most frustrating thing for me. The outcomes of our political system at determined so much more by how we elect people than who we elect. The system is so broken, and people want change, but you're never going to get real change just by putting different people in charge.