BBB is the most valuable to your business. But, the rest of the affiliations depend on what type of company you are operating. Is it a custom home builder? Is it a remodeling business? Are you a design company? Do you work with residential clients or do you work in commercial settings or with real estate investment groups? It all depends.
NAHB is for home builders.
NARI is for remodeling businesses.
NKBA is for designers.
NAHB is recognizable but not too well known. NARI does not hold much weight with customers. NKBA is really good to have if you are a designer. But, you can expand to Diamond Certified and NCIDQ for more affiliations as well.
Register with an organization that carries weight and value with homeowners. The BBB affiliation is a very, well-known symbol and it resonates well with customers, so look for the affiliations that will provide the best return.