Unfortunately, this is a much harder question than the question of what we think about NCLB. This is one of the reasons why education is so hard to reform. There are no easy answers about how to fix things.
I would start by mandating that there be one national testing system. I would make sure that this test would be a good one that does not simply measure whether students have learned various facts. I would want it to measure their ability to think and their ability to apply things they have learned to actual problems. This would ensure that tests are not simply testing whether students have memorized things. It would instead test whether they actually know things in useful ways. This is, of course, easier said than done.
I would then lower the stakes on the testing. I would get rid of the idea that we are supposed to get every student to grade level. Instead, I might set up a system in which we would monitor every student and require that schools should get the students to improve every year. If a student is below grade level, but is improving, that seems to indicate that the school is doing a decent job.
There are many other things that might be done. I would suggest you post questions like this in the discussions so you can get more points of view.