Oftentimes when we make maps it is based on our subjective interpretation of what is aesthetically pleasing. I would like it if people posted examples of beautiful maps, displaying any phenomena in any manner.
Below I have posted one of my favorite maps. This is an example of a value-by-alpha map recently asked about as How to implement value-by-alpha map in GIS?, and the picture is taken from the GeoVista website.
Citation for the map's makers:
Geovisual analytics to enhance spatial scan statistic interpretation:
an analysis of U.S. cervical cancer mortality Jin Chen , Robert E Roth
, Adam T Naito , Eugene J Lengerich and Alan M MacEachren
International Journal of Health Geographics 2008, 7:57
It would be best for the cultivation of knowledge if people would elaborate on why the particular maps they cite are beautiful.
The reason I believe I think the cited value-by-alpha map is beautiful is that it creates a very simple, but obvious and striking visual hierarchy with which to interpret the standardized mortality ratio's. This is in particular useful combined with the very "noisy" standardized mortality ratio's, and the typically very noisy clusters of abnormally high rates produced by the SatScan clustering technique. One can even clearly see very small clusters around Chicago and Philadelphia.
There are other supplemental elements of the map that make it easy on the eyes. For example, the black background, the heavier white outline for around the states and the white outline for the states (that is blended the same as the attribute values). Maps with many polygons can particularly be distracting if one does not take care when plotting the polygon outlines.
Also the legend is particularly well created, and effectively demonstrates the concept (although it certainly isn't a typical legend, so took some original creative thought).
Best Answer
RADICAL CARTOGRAPHY showcases couple of really nice examples.
My two favourites:
Eduard Imhof's work, especially his hand-drawn hillshading maps:
As the question does not specify that a map has to be a traditional static map, I would like to propose the Mapnificent London travel times map.
As per usualy, Google are really pushing what you can do with Online Mapping APIs. In terms of map design, the v3 API now gives you greater control over tweaking the underlying base map.
The map is also very user-friendly, but I think usability probably falls outside the realm of beauty.