I've caught my share of cats blues, channels, and flats combined more blues and channels thans flatties. Of the catfish flatties pull the hardest pound for pound. When I have fished below kentucky dam and the mcalpine lock and dam at louisville I never know what may decide to bite when I drifting and bumping cut bait or live bait. On good days when everything seems to be biting I have caught freshwater drum, wipers (hybrid white bass/stripe bass), channel cat, flat head, blue cat, gar, and even those god for saken big head asian carp. I have caught some redfish not tons but enough of them from 14" up to over 40", and I love fishing for smallies biggest one being a 21" smallmouth I got in michigan. For me I would honestly say I think redfish (red drum) and freshwater drum fight the hardest if smallmouth got as big as them maybe they'd give them a run for the money idk. For me I love getting a 15" plus smallie on light tackle. Cats fight, but drum just pull, and never seem to give it be it red drum aka redfish, black drum, or freshwater drum I've heard people call freshwater drum two other things white perch and sheep head. Gar can put up a good fight and give a good aerial show, but just don't have the pull like drum. Hybrids aka wipers (stripe bass white bass hybrid) put up a heck of a fight especially in some current.
But when I have fished the falls at mcalpine near louisville or below kentucky dam when I have been catching multiple species I can always tell when I have a drum cause of how hard it pulls. Now the few really big cats I have gotten fight really well, the few blue cats I have gotten pushing or 40" didn't compare to drag peeling freight trains that bull reds are that I've caught out at oil rigs in Louisiana. Only thing that has pulled harder than a big bull red that I've had experience with are sharks. I'm like rich for as fierce as musky seem the three I have caught granted weren't big only between 35-40" kind of just gave up after a rather short hard fight.
What I love about smallies is often when I get a good one and get it close to the boat it's like they get pissed seeing it and will a lot of times make a last run. Never have gotten a tarpon or schnook would love to though I'm gonna have to change that hopefully with my dad as he just got a place in florida to retire to so hopefully will be making trips down there to fish with him. Can't find a picture of when I was musky fishing in michigan and don't have any good ones of any bigger catfish. People say steelhead fight great I don't know that's something I need to change as well haven't gotten one of those yet either.