I love it all!
Most reputable sushi places use very fresh ingredients, and the chefs are well-trained in the preparation. I've had plenty and never got sick. I like salmon, tuna and yellowtail. Of the cooked stuff, I especially like eel (I know, sounds gross, but it's good) and soft shell crab.
I love most oysters too. It's the same issue: you have to have a reputable source and know it's fresh. I've eaten tons of raw oysters and I've never been sick from them. Ever.
Oysters are very varied in size, texture, and flavor. It depends where they come from. I'm lucky in that I can get really good Wellfleet oysters all year-round. Also, there are a few places that fly in oysters from the west coast. I love the kumamotos; they're so different from New England. Whereas Wellfleets taste sweet and a little like the sea, kumamotos are small and creamy and not at all briney.
Great thread, Amanda. YUM!