I once found a gem of a city map on Deviantart, but can't find it anymore, unfortunately...
Anyway some of the city maps I like:
Your Liberty City map... I have seen that map popup lots of times in Google images, when browsing for maps.
Coyotemax's city:
http://www.cartographersguild.com/fe...zamentoMap.jpg
Djekspek's City of Tyrborg:
http://djekspek.deviantart.com/art/C...borg-152392679
Some other cool maps:
http://stormcrow135.deviantart.com/a...idges-60910668
http://domigorgon.deviantart.com/art/Town-Map-129613666
This one I just discovered... wow:
http://khorghil.deviantart.com/art/W...City-142477638