*.3ds, IMHO It produces the smallest file size, keeps all the mapping information under almost all conditions, keeps very faithful color, opacity and specularity settings. (A *.3ds file typically is less than a third the file size of an equivalent *.obj file, and the same for an equivalent *.vob file.) However, many programs that generate a *.3ds file, automatically crank up the specularity (shininess) setting to about 33%. (For example, the model-builder might have made a wooden bridge that really wasn't supposed to be shiny.)The model author should be checking the final *.3ds file for excessive shininess if it wasn't intended, but many do not. So, for some imported *.3ds models, you might have to reduce the reflection setting in Vue for all or parts of the model. But this is a pretty mild drawback.