We can always recommend the best option for your project. All styles require editing to a different degree, very much depending on the type of object and the desired effect.
No Shadows
Completely clean background. It helps with collages and open the possibility for further editing. Object may look as floating.
Natural Shadows
This is usually a shadow on the resting surface with a small footprint. It comes naturally with studio lighting. White background is still achieved.
Simulated Simple
A simple cast shadow effect. Requires editing.
Simulated Complex
Artificial but natural looking shadow. Requires skilled editing.