The way you've worded yur question could be construed as a little confusing.....do you mean the easiest to get a hookup on or once it's been hooked the easiest to land. Once again, as others suggested pinpoint your question to a given area. ie. Pacific Northwest Otherwise you are going to get answers for fish from all over the world.
For me in the Pacific Northwest:
Easiest fish to get a hookup on would have to be rainbow trout....tough to hook over 50 salmon of any species in one outing yet you can do that with trout fairly often.
Easiest to get to hand would also be trout if they are the Fraser Valley 3N fish released in C&R lakes that allow for huge growth potencial....their bodies grow too big for their fins. They can't jump, they're sluggish and there's very little fight in them. Its even worse once they've figured out that they're going to be released anyway. I've caught lots in the 10 lb. range that don't even compare to a 3-4 lb. Kamloops rainbow, Girard, or Blackwater strain rainbow.