Ushuaia's seafood is the draw. Centolla (king crab) is the local speciality — harvested from the Beagle Channel and surrounding waters, it is served in almost every restaurant in town, either steamed and cracked at the table or incorporated into dishes. The quality is good but the price reflects it; expect to pay significantly more than in Buenos Aires. The local centolla is seasonal (generally May–October for legal harvesting), so outside that window check whether what's on offer is genuinely local.
Merluza negra (Patagonian toothfish) is another local catch worth ordering. Lamb from the estancias of Tierra del Fuego is excellent — the animals graze on subantarctic grasses and the meat has a distinctive flavour.
Av. San Martín has the densest concentration of restaurants. Most are reliable and tourist-oriented; quality varies but few are bad. Several places specialise in centolla degustaciones — tasting menus built around the crab.