578 Hinano St., Hilo
There are only about 8 seats at Chef Igarashi's sushi bar, and you will have to line up for them (reservations book up months in advance). Igarashi focuses on perfect, incredible fresh sashimi and sushi—that he doesn't dress up with much beyond rice, wasabi, and shoyu—in short, get the omakase.
Moon & Turtle
51 Kalakaua St., Hilo
Earning rave reviews for its daily changing, farm-to-table, ocean-to-table small plates, this sweet little spot justifies a trip if you're not staying in Hilo (also consider a stop here for dinner on your way back from Volcanos National Park). The plates are truly inventive, blending the best of Hawaiian ingredients with Asian flavors, and they always sell the best of what's available, which translates to only having enough for a few of some plates. (The chef-owner Mark Pomaski got his training from Roy Yamaguchi, so the mastery makes sense.) Make reservations, though you can usually grab seats at the bar.