Your question is ambigious. Are you asking what a different system would look like, or how we would get there?
As for the first question, there are many obvious ways to improve the system. Here are some suggestions: abolish the electoral college, abolish the Presidential veto and pardon, abolish the Senate, abolish lifetime Supreme Court terms, add term limits for Congress, publicly fund political campaigns and outlaw campaign contributions as illegal bribery, allow public recall campaigns against the President, Congress, and Supreme Court, etc.
As for the second question: "The biggest problem with the US is that we haven't had a political revolution in 250 years."
An Orwellian dystopia has grown unabated, regardless of who is in power. Remember that the Snowden revelations came out in the Obama administration. The pervasive surveillance that has invaded every aspect of our lives is not even a political issue that leaders debate. The political duopoly has been bought off. I'm not sure exactly who you think "the good guys" are.
Your question is ambigious. Are you asking what a different system would look like, or how we would get there?
As for the first question, there are many obvious ways to improve the system. Here are some suggestions: abolish the electoral college, abolish the Presidential veto and pardon, abolish the Senate, abolish lifetime Supreme Court terms, add term limits for Congress, publicly fund political campaigns and outlaw campaign contributions as illegal bribery, allow public recall campaigns against the President, Congress, and Supreme Court, etc.
As for the second question: "The biggest problem with the US is that we haven't had a political revolution in 250 years."