GAME DESIGN

Clickteam Fusion :: Excellent for 2D and with plugins, 3D Game Design

Unity 3D :: A Great all-around 3D Game Design program.
Uses many languages you may already know.

Unreal Engine 4 :: Epic Megagames, makes of Unreal Tournament, gives you their tools

Blender :: Free & Open Source 3D Creation Suite.
Much like 3D Studio Max and Maya, and compatible with many expensive alternatives.

Top 10 Game Design Software Programs: Getting Started On That Long Term Project

Frostbite Engine by EA. The tech behind games like Mass Effect and Battlefield.

23 Noteworthy Engines Some have been listed already.