Snazzy Maps - Simple & Free To Use Themes for Google Maps
Printmaps.net - Make high-dpi maps for print applications within minutes, using the Printmaps editor. Put custom geo data such as routes or shapes onto your map, or geocode hundreds of addresses to populate your map with POIs.
Stamen Maps - Turn any OpenStreetMap location into a watercolor painting
Windows Maps - Maps is your guide to everywhere.
MapStyle - MapStyle is a huge library providing a plethora of options for styling the map with detailed customization support.
Google Maps - Find local businesses, view maps and get driving directions in Google Maps.