Well, I'm in the minority here...
I like singles and I really like Owner cutting points.
Singles:
Several seasons back, trebles were outlawed on the Deschutes River. I had been a treble user and this forced me to deal with singles.
My hookups remained steady and I lost far fewer lures to snags using singles.
Now, I almost never fish a treble on a lure except for an occasional store-bought plug.
Trebles are legal again on the Deschutes.
Cutting points:
I am beyond impressed with how the little size 4 Owner cutting point will hook and hold big steelhead.
For valley summers I like to use a tiny, yarn offering and the above hook is perfect for it.
I've had fun giving fish to my "big hook" buddies with the little yarn bug and size 4 still in the fish.
The Owner size 4 model # is 5111-071
The 2 is a nice hook also.
Edit:
When using singles on weighted, casting spinners I would recommend using a split ring of the appropriate size between the hook and the spinner wire.
If the single has that extra bit of "wobble" it will hookup better and it will be harder to Mr. Big to throw.
I like to incorporate swivels into my salmon trolling spinners at the hook as well.