I own and like these, roughly in order of preference:
1. Ralph custom Arclite 420V
2. Crawford skeletonized drop point ATS-34
3. RJ Martin Handyman D2
4a. Emerson LaGriffe
4b. Yurco Wharncliffe
5. Dozier Canoe
I like these also:
1. Kit Carson Small F4 (a bit too small for me)
2. Kit Carson Large F4 (about right)
3. Microtech Medallion
4. Chew NeckBone (not sure Larry is making these anymore)
5. Nealy mini Pesh Kabz
Bargain value: Camillus Arclite in 420HC (underrated steel, especially for neck knife)
Neck knife needs to be, IMHO:
1. 2.5" to 3" blade
2. stainless (salty sweat factor)
3. very light, i.e. 1/8" stock and skeletonizing helps
4. secure... with an index finger notch/cutout/guard
5. good kydex sheath, solid retention, quick snap-out
6. suspended by breakaway chain or paracord with breakaway feature