[willy]

Pound for pound for me so far is the hybrid stripers we have in fresh water here, will bend your rod until you have them in a net in the boat. Will come clear out of the water by at least 2 feet and dance on top trying to shake you off like a sailfish.
But there are a bunch of other fish I have not caught.
A hook jawed wild rainbow in the Delaware river runs on a fly rod will test you to the limit and a big Lake Trout will break your rod if you don't get him up in the first minute or so from a deep lake. As a matter of fact if you hook into a real big one and don't get him turned from bottom in the first minute you are going to loose him. If you get him turned with heavy enough tackle and get him up 50-60 feet then he loses strength fast due to nitrogen in his system.