Chinook that are big enough that you could drop the average steelhead down without touching the sides.
I know one of the Salty Dogs is going to say that if you took a 20lb steelhead and a 10lb tuna and put a hook in each of their mouths, threaded the line out their vents and tied them together tail to tail, gave the steelhead a head start, the tuna would snatch the steelhead inside out and run off with the remains!
Years ago, I worked on a fishing boat out of Rockport, Tx.....one day, bored, I decided to bait a handline for blackfin tuna....oh my God...almost tore me up, I am a small guy, but that thing, at about twenty #s, almost did a number on me...never again by handline
I don't fish saltwater so it has got to be STEELHEAD!!! Bonus points if it is hooked on a skating fly where the fish comes out of the water and smashes the fly and takes off with your line and half your backing making you look stupid running and stumbling down the bank to catch up.
Chinook are strong fish, over rated in my book since they don't do a lot of jumping and zooming around.
If you get the chance to fair hook a fresh sockeye those things are like a turbo-charged Summer steelhead and will leave you standing on the bank with your line wrapped around your neck.
I would say from my own personal experience it would be summer steelhead for their acrobatics. Gotta love it!! I have also been on charter albacore trips where I think they are the KING of all fighting fish. Handlining these guys on a charter provides most meat to my jars but they always let us catch a few on the rods. My arms were always sore afterwards and you would think maybe a 20+ lb'er and it always turns out smaller. Fighting an Albacore will tear you apart on a rod.... he is not too forgiving and will rip you a new one.
Okay ....there is my vote!
Springers can be fun too!
A dorado (mahi mahi) is pretty spectacular, but not many get to try it...
Summer steelhead are, too, but it's tough to beat the stamina of a coho in fresh water...sizzling runs in shallow pools are very cool.
Years ago on a vacation in Hawaii, my brother-in-law & I went on a charter...my first & only experience with fishing in those waters. I hooked & brought in two Wahoo (also known as Ono). The deckhand lost the first one at the stern, but landed the 2nd...about 35#. The power & speed of those fish through the water is unbelievable!