I find the city maps to be OK so long as I take the time to make a few notes on them. Most of my notes are landmarks, bridges, distances, and alternate paths.
I often just use tourist or transit maps because they are cheap, often free. Sometimes I just do a sketch map in my fieldbook.


You can download topo maps from USGS and use them to make your own maps.
http://nationalmap.gov/ustopo/index.html

or for Canada
http://atlas.nrcan.gc.ca/site/english/index.html