We spent 3 nights in Hilo, 4 nights in Waikoloa, and 3 nights in Kona.
KEN'S HOUSE OF PANCAKES, HILO: For breakfast we ordered mac nut pancakes, coconut pancakes, plain pancakes, and an omelet. We enjoyed sampling the different syrups (guava, passionfruit, coconut, etc), but would skip the coconut pancakes next time. Huge menu, food was fine but not worth going back to.
HILO LUNCH STOP, HILO: Despite our being from CA (us from SF and our friends from LA), we'd never been to an okazuya before. Definite hole-in-the wall, we had fun picking out the items for our lunch boxes. Lots of variety, and a great option for packed lunches. Maybe it's a Big Island thing, but all the Spam musubis we had (four different places), this included, had too much rice compared to the Spam.
KILAUEA LODGE, VOLCANO: Very solid meal, but not memorable except for the fact we had antelope.
HILO FARMERS MARKET: Spent a fun couple of hours at the Saturday farmers market, snacking away on the fruit, musubis (hot dog! Korean chicken!), papaya salads, etc here. One of our best purchases was a bottle of Hawaiian chili water which we lugged around the rest of the island and used to spice up all our at-home meals (esp breakfasts).
LOW INTERNATIONAL FOOD, HILO: Picked up some of their famous rainbow and guava bread. Very faint fruit flavor in the bread, though it was soft and sweet.
TWO LADIES KITCHEN, HILO: Awesome mochi!!! The fresh strawberry with red bean mochi was amazing -- highly recommended!
CAFE PESTO, HILO: Fine meal, nothing special. Fish slightly overcooked.
BIG ISLAND CANDIES, HILO: Huge touristy store. Chocolates are overly sweet but boy those shortbread cookies dipped in chocolate are delicious, and make great gifts.
POKE TO YOUR TASTE, HILO: A total hole in the wall. We came here since Suisun was closed on a Sunday and there wasn't much open. Limited selection of poke (only six or seven) but good kimchi shrimp poke, plus their ahi tasted very fresh. As the name implies, for their plain & shoyi ahi poke, you add your own ingredients such as fresh garlic,seaweed, etc to it.
HIRO'S PLACE, HILO: Another place we visited on a Sunday when other places (Kawamoto's) were closed. In the same shopping plaza as KTA. A lunch counter for takeout, chicken katsu is their speciality -- food was fine but preferred the selection at Hilo Lunch Stop.
TEX'S DRIVE IN, HONOKAA: Good masaladas but try to come earlier in the day when more flavors are available. Also offer a serviceable selection of Hawaiian plate lunches.
DA FISH LUNCH WAGON, KAWAIHAE: Converted minibus serving fish tacos and fish plates in a gravel parking lot not far from Spencer Beach. Tasty and large fish tacos, but not traditional.
ANUENUE SHAVE ICE, KAWAIHAE: Across the street from the lunch wagon. Huge selection of flavors including untraditional ones like ginger lemongrass, lavender lemonade (recommended), red velvet. etc. A great find!
MONSTERA, WAIKOLOA (MAUNA LANI): Distinctly unimpressed by their Chuck Norris roll, but their cooked items (homestyle Korean/Japanese fusion) quite a bit! One of our favorite meals of the trip.
MERRIMAN'S MARKET CAFE, WAIKOLOA (KING'S SHOPS): Came in for a late lunch and generally found the food to be pretty bland. One of our least favorite meals of the trip.
ROY'S, WAIKOLOA (QUEEN'S SHOPS): Always a reliable choice, but didn't seem any different from Roy's on the other islands, though a few more local fish options than Roy's on the mainland.
UMEKE'S, KONA: Our favorite of the poke shops we tried, partly due to their friendliness, such as letting me put in two 1/2 scoops of poke for my lunch bowl (which Da Poke Shack wouldn't let us do). Good selection of 12 pokes and six side dishes.
RAY'S ON THE BAY, KEAUHOU (SHERATON): We came for a late dinner after our manta ray snorkel/dive (amazing!!) since we were staying here and not much was open. Only their late night menu was available, but it was better than expected and the service was super nice. Plus, seeing the mantas gliding through the water and flipping their wings up was really cool!
DA POKE SHACK, KONA: Large selection of poke and side dishes too.
RAPANUI, KONA: Great food but the service was pretty unfriendly, which soured us to the experience. Recommend making reservations as it's a small restaurant.
KA'ALOA'S SUPER J'S, CAPTAIN COOK: The most shady-looking of the hole-in-the-walls of our trip, we would have missed it if it wasn't for our GPS. But OMG, the absolute BEST laulau's we've ever had!!! They offer two flavors: chicken and pork. The chicken is good but the pork is AMAZING. Highly recommended.
MIKE'S TWISTED PRETZELS, KONA: Mike is a reallys sweet guy but sadly his pretzels weren't all that. They were bread, not pretzels. Not even pretzel bread, but bread.
QUINN'S ALMOST BY THE SEA, KONA: Our beach boys in Waikoloa highly recommended this local place so we checked it out. Their fish & chips were pretty good, but I would avoid any "special dishes of the evening" that they were experimenting with, as I didn't like my crusted & seared ono sashimi at all.