We stayed at the Royal Kona Resort when we went… you MUST do their luau “Lava – Legacies and Legends”, it is one of the only ocean front luaus on the island and the performances are spectacular!
On the other hand, it is very commercialized, and if you’re not looking for that, Hilo is a better place to be. I was on the Big Island for a month and stayed below Hilo most of the time, and there is much more scenery without the industrialization, and more of an authentic Hawaiian feel to it.