The problem with the American public school system is that the balance of local-state-Federal control is skewed. Money should be evenly allocated and school boards should have stricter guidelines about how money should be spent (in my home district and i imagine in many others, the bias is on athletics for athletics sake), the Federal guidelines should be focusing more on a holistic approach to education rather than the pointless test-oriented math-reading blitz
I'd rather there be a national core cirriculum (with the ability to diversify based on regional or personal taste around the edges), as well as national teaching standards, with established systems through which teachers can be suspended or outright fired, with more severe consequences for firing and less severe on suspension (to allow underperforming teachers to reform themselves)
As far as the problem of teachers' unions go, you need an environment where teachers aren't going to be afraid that the bean-counters are out to get them (looking for an excuse to fire someone to save budget), but where standards for teaching are also enforceable. Better allocation of funds, along with universal teaching standards, would fix both.
Monster Hunter: pissing me off since 2010.
