Pound for pound.....sockeye.
I never fished for them until a couple years ago in Canada. They are crazier than a summer-run steelhead. We were trolling flies, with no barbs. There's a thump on the bow of the boat ( the fish hit the fly and shot ahead of the boat, jumping under the bow ) the rod goes down; zig-zag running and rolling like a cat in a ziplock-baggie. Of course with no barbs we don't have a snowballs chance....
And that was just the first one. We never did land one, and the only sockeye we ate was the one swapped to a Canadian commercial seiner for a glass of good whiskey.

Second best? I think I'd say marlin, but it might be biased because the hook up and tailwalk is so impressive. But I found that the next 2 fought just like the first one, so it became predictable. First they fight on top and then they sound, and for a very long time. Anyway you look at it, if you like to fish.....make the marlin trip at least once in your life.
diana