My own experience is that no one species has a taste advantage over another.
Instead it has much more to do with water quality and feed, in my opinion.
I happen to love fresh trout and salmon. But the flavor of a trout from a summertime-warm, weedy, muddy pond in Massachussetts can't compare with trout I caught as a kid from pristine streams at 8000 feet in the Uinta mountains of Utah.
The Uinta cutthroat were eating freshwater shrimp from cold, clear, and highly oxygenated water. The flesh was a bright orange. The planted rainbows here in New England were eating, well, something else.
I've noticed the same with warmwater species. I've had farm-raised catfish that was excellent. I've caught the same CC species out of a warm and muddy farm pond, and there was that muddy taste. And I believed I fileted it properly to remove the dark/fatty portions, washed, and marinated it properly.
Now all that being said... Well, you also just have to like fish. Which I do. And develop your own favorite recipes!
Fried fresh fish.
Fish fried fresh.
Fresh fish fried.
Fried fish fresh.
Fish fresh fried.
Fresh fried fish.
Hmmmm.
