Sorcha, I'd never try to change your mind, but what you said is like saying all beers are the same, or all whiskeys are alike.
Where you live you can not get fresh salt water fish, and freshness is critical to flavor. Fish begin to spoil the second you pull them out of the water.Dolphin is the best example; you can see the colors start to fade immediately.
Anyway, my favorite is Salmon. I use the steaks or the thick end of the fillet. Put it on a broiler pan, pour a mixture of butter and a bit of lemon juice over it, add a some pepper, and broil until just a bit brown. Delicious.

I do find fresh water fish a bit on the bland side. Like tofu, you have to add flavor.