Tools > Options > Terrain quality > check show terrain, terrain exaggeration on 2
It gives you a really good idea of what the terrain looks like. Really good if you are flying somewhere hilly / mountainous.
Also, if you are flying in the US, you can easy use Chartgeek or these free Aeronautical chart overlays for google earth. Combine it with the 3d terrain and 3d airspace, and it is really cool. They have IFR charts, Terminal Area charts, Aeronautical Sectionals, 3D airspace, and more.
Index of /maps/Sectionals
Google Earth: The Ultimate Preflight Tool - Plane & Pilot Magazine | PlaneAndPilotMag.com
ChartGEEK Charts for Google Earth