Define what you think is "best."
There is the perception that Davies is the "best" because the richest kids live in that attendance area and there are the fewest English Language Learners.
My 2 sons attended South High, and overall had a great experience. It is a much more diverse school, but much more cohesive than Davies. There definitely are options for academic excellence as well (older son was part of champion team in tri-state math competition and the econ challenge team qualified for the national competition).
At North, as currently the smallest of the three, there is a smaller chance that kids will get lost in the shuffle and probably more possibilities to participate in activities.
All three schools have kids with drugs/drinking issues and all three have a police presence--school resource officers.
The demographic picture of each school can be found here:
Public Information Warehouse - LRFP-Portal under Secondary information.
I might ruffle a few feathers with this comment, but in my experience with knowing students in all three schools and reading news reports, regardless of the school the kids involved in cross country are some of the best (geek sport, I know), and stay clear of hockey players (a LOT of alcohol, parent enabling, and a few sexual assault arrests).