George Town's reputation as a duty-free shopping port is mostly built on jewellery — Cayman pearls, black coral (in regulated quantities only — much of it is now banned imported), tanzanite, and diamonds. The big chains (Diamonds International, Tanzanite International) are on Harbour Drive and Cardinal Avenue; smaller specialists are scattered nearby. Prices are competitive with the lower end of US mainland retail; haggling is acceptable on jewellery once a cruise ship has gone.
For Cayman-specific souvenirs, look for Tortuga rum cake (now a global brand, but invented here in 1987), Cayman sea salt, hot sauces from the local pepper-jelly tradition, and prints by local artists at the Pure Art gallery on South Church Street. The Bay Boutique on Goring Avenue is good for resort wear.
The covered Craft Market by the cruise terminal sells T-shirts, hats, sarongs, and the inevitable shell figurines — fine for trinkets, less so for anything you really want.