The Niven’s River World map by mahks is a truly good map which I believe should be somewhere up in the list of available maps.
The action quickly starts and it combines all important aspects of the gameplay - movement, correctly timed attacks and retreats. As individual parts of the map are interconnected, the gameplay quickly shifts from one front to another. What I also like on this map is that some of the bases in the center and on the top are in reach of long range units, offering a possibility of distant control of enemy bases as well as directly attacking them.