What major is great to get into the designer business?

If you do not want to major specifically in fashion design, jewelry design, etc. then some kind of degree in studio art would probably make the most sense. It also depends on what other career routes you are considering aside from design. However, if you feel that you have the talent to be a designer at big high end companies, than your degree can be more flexible. I know someone who was an engineering major and now has a career designing jewelry for Tiffany.