Toughest freshwater fish in USA?

[dvdegeorge]

King salmon

[fallsflight]

For drag burning and acrobatics, I say steelhead. I haven't fished for salmon but quite a few folks vote for them, too.

I agree with the drag burning and acrobatics for steelhead and i would also include the salmon for their drag burning ability.    A nice fresh Chinook/King Salmon on the line with put up one good fight for sure. 

[misfire]

Bream, like catdaddy stated, you would never land one if they grew to 10 pounds or more

[flintlock]

Chinook/King over 20lbs for me.

[ILIKEHEVI-13]

Pound for pound a smallmouth. If they grew any bigger it would be dangerous to swim. 

I would have to agree.  A bluegill would be right there with it. 

And I believe for a trash fish the grennel may beat them all. 

[Solid Snake]

Smallmouth

[sippy cup]

smallmouth

[ILIKEHEVI-13]

I'll tell you guys that I had the priviledge of cathing one of these grennel like in late Feb or early March here that probably would have weighed 10lbs.  The water was fairly cold and this thing still put up a great fight.  I have caught some 3lb grennel if I remember correctly in my younger days that fought as good as any 3lb fish I have ever caught.  It's like catching a 6lb catfish.  But pound per pound I do believe they probably would even defeat the smallmouth.  

[Woodsman4God]

For sheer pull without the Pound for pound arguement, if you have ever put a hook in a big Muskie ( over 48 inches ) you'll say nothing else.  On the best day we had on Lake St Clair ( one of the Best Muskie fisheries worldwide) We landed 4 and lost 2, the 2 we lost we only saw each of them once, One as it spit the hook out after 30 minutes about 50 yards away and it stuck in my shirt (almost my stomach )after flying all that way to me, and the other ended up breaking the crank on a saltwater reel that we have pulled in Big red snapper with. 50-60 pounders. We thin both would have gone 55 to 60 inches as our other ones were 45,48,49 and 51 inches. Muskies are tough up to 45 inches but then they get big and nasty after that its a different fish altogether

[Grobec1]

Alligator Gar or Choupique.

[turkey slayer]

bluegill, if they grew to 10 pounds they would pull you in and eat you.