I preferred Macky's Shrimp truck in Haleiwa over Giovanni's. I found it less greasy.
+1 for Marukame Udon
At the King Village Farmer's Market there's this guy who sets up a table there on Friday night and sells tuna poke. Huge portions in a square take out container on a small bed of rice. He's known as.. the Poke-Man ....
He sometimes sells out though so don't go too late.