...there was Mac Made Easy.
A long time ago, you had a couple of retail choices if you were a Mac user in Honolulu: look for the lone Mac shelf in the corner of a local computer store (remember Software Plus? MicroAge?) or mail order.
Today, Apple is thriving. Honolulu now has its own Apple Store in Ala Moana (and one rumored for Maui too). Mac Made Easy moved to a larger location in Nuuanu and seems to still be fairly successful even with Apple's corporate presence just miles away. They've concentrated on their niche: a knowledgeable staff; a wide range of Mac-specific products; and a willingness to help anyone, regardless of skill level.
My only gripe is that their parking (in a strip mall) is extremely crowded. It's difficult to get parking and all the spaces seem to be sized just enough for a compact car to fit (let alone the monster SUV most folks drive today).