Originally Posted by Bex_123:
“ I love tuna and salmon sashimi and I was just wondering is the fish you buy from the fresh fish counter at a supermarket fresh enough to eat raw? Or would that just be a ridiculously bad idea?
Is the fish they serve raw at sushi restaurants as sashimi much fresher/different to that sold on the fish counter?”
It's reasonably safe, but only if you know your seafood well.

Best to seek help from a fishmonger (at fresh-fish counter or a local fishmonger shop). Explain why you're buying and he or she'll help you in selecting edible raw seafood, e.g. safe to eat it raw.
I have to point out that not all sashimi are raw, though. Some are cooked. And not all are seafood either. Meat (chicken, beef, liver, pork, horse, etc.) and vegetables can be used as sashimi. The word sashimi itself basically means 'cut body' (in context of a topping) and 'sushi' means 'vinegared rice'.
For what it's worth, eating all fishes raw in sushi at home actually isn't that common in Japan. That's a U.S. thing. Sure, there are some in Japan who eat all fishes raw at home, but everybody knows they're certifiable.
Salmon - it's safer, better, easier and tastier to opt for a packaged salmon. No one eats raw slices of a salmon straight from a river or similar. They usually ice or freeze it first, or sometimes marinate it. Then they serve it raw.
Tuna steak - usually marinate, dry-pan, sear or (less commonly) boiled, but can be eaten raw if it's been frozen and marinated. No need to do this if it's purchased from a trusted fishmonger.
Prawns or shrimps - usually dry-pan, sear or boiled.
Squid - usually broiled in soy or similar stock, or dry-pan, sear or 'flash-cook' in a pan, usually about ten seconds.
That's all I can remember. (Sorry, Gran.

) But I can ask my gran if you want more info on other seafood.
Edit:
Originally Posted by Lainiomonkio:
“To be fair, you're not meant to eat the rice cold. It's meant to be at room temperature so you can taste the seasoning of vinegar, sugar and salt. Cold rice is horrible and goes hard and chalky but room temperature rice should be sticky, soft and very palatable. Mmmmmm... I want some now!”
I agree with this.