What is the best track alignment?
There is no single "best" setting. The best alignment depends on the car and the driver.
The more experienced the driver, the more aggressive alignment settings (more negative camber, in particular) is generally ideal.
Too aggressive of an alignment can cause premature tire wear. A car that is aligned to be loose, or eager to turn, can be prone to spins when driven by less experienced drivers.
Read more at the track alignment page.