Well, if waders were out of the question, say if the weather was nice, I would agree, with you on the line thing. You can't land a fish on crappy leader, and also you can't get a good hold on a fish with a dull hook. And also you can't see that big steelhead or trout without proper vision altering devices, polarized sunglasses, never leave home without'em; but certain tactics don't require them. Oh yeah, don't forget the 10ft. bamboo stick for alterting napping rattlers when your in the country.
for winter steelhead absolutely 5mm bootfoot waders,in the summer featherlights being warm or cool either season makes for more relaxed fishing which means better concentration, mending and all around bliss
A wife that encourages such behavior is definatly at the top of my list. then waders, I can't imagine spending more than about 30 seconds in a 40 degree river and having fun unless it's 90 or more in the sun.
For Stream fishing, I would say Poloroids. I don't consider them necessary for lake fishing but I don't do much lake fishing.
For lake fishing I would say a net. I really like it as it allows me to get the fish in a lot quicker to release.
As a WSU alum, I would be remiss to omit Busch Light. But Jim Beam is also nice. But the ultimate piece of equipment is hope - particularly when the fishing is slow, I think that it is the unreasonable confidence that each cast will be the one that pays off.