I'm not even sure how to start and it would be dependent on what you regard as "hard fighting ability". It would be hard to pick three more different fish.
If you place great emphasis on acrobatics, the dolphinfish will win hands down. If it's speed, the spaniard will win and if it is the ability to bust you off, it will be the spangled. Conversely, if you regard speed highly, the spangled will trail the other two considerably.
I personally don't regard the spaniard as a hard fighting fish but that is partly because the poor spaniard is generally being hooked on heavy GT gear and getting its butt smacked. I love dolphinfish but then, every one I have hooked has been on relatively light tackle which gives the fish an opportunity to really perform. Spangleds are tough as hell but that is driven to a large degree by the areas we hook them. Let the fish have its head and it's a goner.
On eating ability, I regard spaniards highly but dolphinfish is excellent provided it is really, really fresh. Spangled is ok but not my favourite fish.
