I get this question a lot. For those who ask it, I'm not intentionally trying to skirt the question. It's just that it's a highly subjective topic! What do you mean by "good"? Does it mean highest SAT scores, highest rate of graduation, best football team, best cafeteria, greatest amount of tenured teachers...I could go on and on.
Most realtors will give you a variety of sources for your own school research. Some include:
U.S. News Rankings
PSK12.com Rankings (by Year)
So don't take it personally when we don't exactly answer your question! =)