SOG Flash I
CRKT Pazoda partially serrated
Kershaw Leek
Ontario RAT I
Byrd Cara Cara 2
Honorable mention:
Boker Plus Urban Trapper G10
SAK Alox Pioneer
The Flash was a birthday present, my first pocket knife, and taught me that I have big hands for that kind of assisted knife.
The Pazoda taught me that I hate serrations, and that not all folding knives have the same flipping action.
The Leek taught me that I like wharncliffe blades, but not too thin, and all black is cool, but assisted opening maybe isn't all that it's cracked up to be.
(At this point it gets fuzzy which came next; I tended to buy knives a few at a time. Honorable mentions were part of the same purchases.)
The RAT taught me that I like hefty knives that fill the hand, and that great knives can be inexpensive, and that I'm never carrying that in an office.
The Cara Cara 2 taught me that lighter, big and capable knives are great in a backpack or briefcase/messenger bag, and that I don't particularly care for FRN handles.
The Urban Trapper taught me that I really like light titanium flippers at 3.25"-3.5" range, that flipper tabs can be too sharp, and that titanium pocket clips bend REALLY easily.
The Pioneer taught me that I love having tools with a knife and that off-center and crinked blades REALLY REALLY annoy me.
Every knife teaches you something about what you like. Sadly, it often takes purchasing and spending time with them to glean what that is. Maybe someday I'll be better about learning just from reviews.
The Flash was passed on to my wife, along with the Leek. Not that she ever carries a knife, but she'll pack one when camping, and I think the Leek is her preferred.
The Pazoda was passed along to my son, who's very happy with it and doesn't particularly care about material, action, et cetera - it's just useful and fun.
The RAT is still around, and comes out when we need a harder use knife - for example, carving jack-o-lanterns.
The Cara Cara 2 is also still with me; it sees no pocket time, but after being used and (inexpertly) sharpened by me (it's sharp but cosmetically scratched), I keep it as a backup around the house. See also jack-o-lanterns.
The Urban Trapper is on hiatus but will be back when I spend time in an office again. It's a great knife, I just with the flipper tab wasn't so sharp.
The Pioneer is also on hiatus; I've added a Gerber Dime Travel to my pocket in its place. I love the size, hate the blade, which has managed to inform and focus my traditional knife collecting plans.