Unity - The multiplatform game creation tools for everyone.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
Corona SDK - Cross-platform mobile app development.
Godot Engine - Feature-packed 2D and 3D open source game engine.
BuildBox - Buildbox is a new video game maker that is extremely easy to use.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.