The Spit has several seafood restaurants and fish markets where you eat what came off the boats that morning. The Fish Dock and Captain Pattie's Fish House are the best-known, both serving halibut in various preparations — grilled, battered and fried, in chowder — alongside Dungeness crab, Kachemak Bay oysters, and fresh salmon. Prices are honest by Alaska standards (which means elevated by the standards of anywhere else), and the quality is high.
For a cheaper option, walk to the fish market end of the Spit and buy fillets to cook yourself if you have access to a kitchen. Or look for the clam chowder places where a bowl with sourdough bread covers a meal for a reasonable price. Homer is not a fine dining town, but it has some of the best fresh seafood in the state.