SketchUp - 3D for Everyone
Unity - The multiplatform game creation tools for everyone.
SmartDraw - Instead of starting with a blank screen, SmartDraw gives you the exact template you need.
Godot Engine - Feature-packed 2D and 3D open source game engine.
SketchBook - SketchBook is a professional drawing or painting application that allows designers, architects, and concept artist to sketch their ideas and create adorable illustrations in no time.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.