yeap. I always save original quality, and images with layers, as .PSD. If a texture doesn't have any layer I go ahead and save the original as a .TGA and the same with all final textures. I usually save .JPG for images I'm posting on the internet since the jpeg compression can distort images. .PNG format also works well as a compressed images format without noticeable quality lose. Plenty of other good formats with their own purpose, but those main three you listed at the ones I use the most.
TGA for games with alpha...unless it calls for something else.
PNG for cool transparencies on web and games.
JPG for large photos.
GIF for thumbnails and simple animations.
PSD for previewing game textures in XSI as I paint them.
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CMB, this page might be informative for you. Games use many different file formats, a few of which are discussed here...
http://udn.epicgames.com/Two/TextureComparison
PNG for cool transparencies on web and games.
JPG for large photos.
GIF for thumbnails and simple animations.
PSD for previewing game textures in XSI as I paint them.