Basically anything between Northbrook and Lake Bluff, including:
-Northbrook
-Deerfield
-Highland Park
-Lincolnshire
-Buffalo Grove
-Lake Forest
-Vernon Hills
-Libertyville
-Lake Bluff
-Lake Zurich
-Barrington

All of these towns combine to make up two very strong wards.

Stay away from North Chicago and Waukegan. Gurnee and Mundelein are hit and miss because, as housing gets cheaper as you move north, the riff-raff population increases as well.