Typically, the only fit-to-eat raw fish in a grocery store are the fillets that you cook up at home. All that plastic-wrapped, fast-foody, or even made-to-order sushi really should be off-limits. (Don't be fooled by pretty packaging.) However, when the craving for quick 'n' easy takeout maki strikes, there is an exception to the rule: a real-deal Japanese supermarket in Japantown, where you're reassured by an "arigato" on your way out. Nijiya Market has a wall-length selection of fresh-rolled spicy tunas, Californias, and shrimp tempuras; highly edible maguro, saba, and unagi nigiri; even seaweed and octopus salads. It's as close as you'll get to superior sushi without sidling up to the bar—and for a fraction of the price. 1737 Post St., S.F., (415) 563-1901.