The Fraser Insitute, a Canadian think tank with high reputation in Canadian economic, social, and educational research and development, has released its "Report Card on Ontario's Secondary Schools" of 2001 edition.

Based on last 5 years provincial ranking, here are top 5 public high schools in City of Toronto. (includeing Toronto DSB and Catholic DSB)

R. H. Academy
Woburn C. I.
Albert C. I.
Martingrove C. I.
Agincourt C.I.

This information will help you to chose high school for your kids.

Reference:
Report Card on Ontario's Secondary Schools, The Fraser Insitute., 2001.
www.fraserinstitute.ca