This thread skews a bit toward what some would say are ... "lesser knives." Says to me there IS some sentimentality to the game of steel.
For me, it's probably the 4.75" handmade J. Martinni leuku (plain, birch handle) my parents picked up for me at his factory in Finland in the mid-60's when I was really too young for a knife. Apparently Mr. Martinni engraved the Nordic reindeer/sleigh caricature sketch that's on the blade and signed it and named the town his factory was in at the time. My most used outdoor knife over time.
The alternate would be my original '60's(?), maybe early '70's, Tekna dive/boot knife with its miracle factory sheath. The first ones were allegedly Seki City babies of some 400-type steel, and apparently I got a GOOD one where h/t is concerned. Great handle for paracord/leather wrap; I also wrapped the sheath to eliminate the 'open' design. Been with me nearly as much/as long as the leuku and carried in every conceivable configuration on every conceivable part of my body or clothing with that sheath. Man does it take to a strop.