Carcassonne

You draw and place square tiles to build a medieval landscape of cities, roads, and fields. Then you decide whether to put one of your wooden followers on the tile to claim points. You get points when a feature is completed. You can try to sneak into a city someone else is building to share the points. The rules are very brief and easy to grasp. It plays smoothly with two people or a larger group. It is a staple that you can introduce to almost anyone without much hassle.