For collectors, you really only need the areas that you covered. Props, statues (unleashed fits here), figures (both 12" and 3.75") and vehicles. IMO, Hasbro dropped the ball with the 12" license.
Sideshow recognized that opportunity and they will reap the benefits.
For kids, you need role play, 2" GH figures (no small parts), and MAYBE larger scale figures (Jedi Force) plus select corresponding vehicles/playsets - very few.
Now the question is where do the transformers and choppers fit in? What about Force Battlers and Attactix? How about Legos?