What programs and software are needed to develop video games

For the programming part its usually Visual Studio c++ or C# depending on what programming language you want to use.

For the art side of games, software such as Maya, 3ds Max, XSI are used for the 3d models and animation.
Photoshop is usually used for the textures.
And some sort of level editor such as Hammer, Radiant, Sandbox, UnrealEd, ect.