With hundreds of traps lining the outside of the store, you can’t help but feel like the lobster at Oyster Cracka’s is among the freshest on Nantucket island. So while this little seafood shack offers an array of grilled, fried, and raw options, we think the lobster rolls make the most worthy lunch — large chunks of lobster with a dabble of mayo, stuffed into a lightly toasted, generously buttered bun. At $21.95, the price is about average for these parts; sure, it’s not bargain-basement, but this is a roll that can compete with the greats of the island.