Daz 3D - Bryce 6.1

Bryce is an excellent 3D landscape program.  Most 3D programs out there cost thousands of dollars, but Bryce is very affordable at just $100.  There are a ton of quick presets for you to use to create realistic images in minutes.  For example, you can drop in ready made mountains, skys, water, ground materials, and basic shapes like spheres and cones that you can combine to create cool looking objects.  You can also import most 3d model formats, which allows for an infinite array of scenes that you can create.  For example, I've imported figures from Poser into my scenes, and objects that I've created in Wings 3D (a free modeling tool).  You can also import figures from Daz Studio, a free alternative to Poser.

I've made scenes of islands, waterfalls, the lady of the lake holding Excalibur out of the water, deserts, a scene where people were waiting for the bus in the fog, etc.  Really, the sky is the limit with this program and it's easy enough to use that anybody can do it.