The urban environment has always been my favorite for gaming ground combat as IMHO it provides the toughest tactical situations. In most other environments, there are some fairly simple things to do in order to increase your chance of success: scout large areas, use artillery or air-cover, approach using bounding overwatch, take the high ground, etc. Although these maxims have value in the urban environment, there are many ways to defeat them. As result, good generalship tends to look like a series of very small, carefully calculated moves. As I guy who likes measures success by how one manages their infantry, urban terrain has always provided an interesting challenge.