It depends on how you cook it. The whole fish needs to reach a temperature of 65ºC enough time to be safe, so cooking it on a grill or a griddle won't do.
If you have a freezer suited to freeze fresh food (four-star), like most people do, freezing the fish by yourself before cooking it is safer than just cooking it.
This. Also, making sushi by myself, I can use the right dose of fish and rice for a balanced diet. Sushi is also perfect for me because I'm not very good at cooking fish alone, I can cook it well for risotto, sauces for pasta, battered or breaded deep frying and stir frying with vegetables, I can also make a good mussel soup, but I suck at roasting or grilling fish. About shellfish, some, as shrimps, lobsters, clams and mussels, are better cooked, but some others, like oysters, are far better raw. And as much as I love cooked scampi, raw ones are even better, particularly if they have eggs, that raw are as good as caviar, maybe even more.