Most fish don't have strong flavor when fresh, you are correct, but can develop stronger flavors if they aren't fresh.

I think sardines (and other oily fish) taste fishy. But in a wonderful sardine fishy way.

Salmon tastes wonderful, always, just like salmon. Not the same kind of fishiness at all. I can't remember ever having salmon that didn't taste good. I would eat it every day if it didn't cost a mint.