Cultiva Plugger Single S-125M
Brilliant salt water single hooks for replacing trebles on bass plugs. Sharp and corrosion resistant. They're not the cheapest but are one of the sharpest, long lasting and strongest hooks available. The 1/0 is perhaps the go-to if you're looking at replacing a size 4 treble. Adjust from there... Work brilliantly on metal casting jigs too.
Ben's an idiot so hasn't added a full category run-down yet. We're sure he'll get on it shortly.