In everyone's personal opinion what is the best way to make money. What is the money makers doing in Graphic Design. I want learn anything and everything from the very best and I believe they are right here on this forum.
Reusable 3D content is fairly big business at the moment (I guess you can think of it as 3D stock). Checkout sites like Daz3D.com, Renderosity.com and RuntimeDna.com. Of course to get as good as some of the guys on these sites takes a lot of time and skill, but the people at the top can make a pretty decent income from it.
The designers who are making money are the ones with multiple skillsets (2d, 3d, Flash, HTML, CSS, etc). It used to be that there were web designers, graphic designers, and 3d designers - all separate from each other. Now...not so much. Sure, it's ok to specialize, but being able to be a one-stop source of talent for your client or employer will keep you very busy.