I have been trying to do this for some time and now I have done it: A random map creator. It is in isometric view so I don’t have to worry about the graphics too much. All the graphics seen are taken from opengameart.org.
This is a small map. Creating a map with 50×50(only one direction/times two for real value) will result in 20.000 tiles to be generated(Like seen below). That.. took some time(about 15 minutes). I tweaked the values afterwards to create some more landmass.