Tools I use, or am familiar with.
My Image editor of choice, I use Gimp for everything form Photography, texture generation, and pixel art.
Construct Classic is a great 2d game maker, that exports to DirectX9. There are many plugin that expand an already capable software.
Construct 2 is a new software by the Scirra team. Construct 2 is targeted towards creating html5 web games.
A useful sound generator (when you are going for a classic video game sound)
Unreal Development Kit
I have years of experience from mapping for various Unreal powered games, making the UDK a natural choice for 3D games.
An easy to use 3D modeling program that is great for props, and decorations.
Unreal Modders Haven