Since everyone else is posting pictures of their knives, here's mine:
It's nothing special on it's own, but the story of how I came into it makes it special to me.
Back when I was young and had two feet and was out playing Good Guys vs. Bad Guys every day, I happened to find myself behind a car on the highway that caught my attention due to the nervous "guilty-of-something" look that the driver was giving me in his rear view mirror. I ran the tag, and sure enough, it was registered to some other vehicle. I called for an assist, planning on just following him until a few friends could show up and join the party, but before I even finished making the call, he rabbited on me.
Oh yeah. It was on. Lights...siren...get him!
I chased after him, and he took the next exit, obviously trying to lose me in the neighborhood. I kept on him as he turned into one of the local project apartment complexes, and at the first corner, he took it too wide, hit the curb, and dismounted his tire. Slowing to a stop, he bailed out and started running. I chased him for about a block in my car because he was so dumb that he was running right down the sidewalk, but then he wised up just before I could pass him and cut him off and he ducked between a couple of the buildings where my car couldn't go. I slammed it into "park", yanked the keys, and jumped out after him. He had a head start and I was burdened down with a vest, a duty belt and boots, but I was in damned good shape back then and I regularly ran distance training for just such an occasion.
I managed to keep him in sight and was actually gaining on him pretty quickly when he rounded another corner and ran smack up against a high fence separating this complex from the equally crappy one adjacent to it. He was trapped.
As I rounded the corner, he was just turning to face me and pulling something out of his pocket. Not knowing what it was but sensing danger nonetheless, I stopped quickly, backpedaled a couple of paces, and drew my pistol just as he fumbled the object in his hand and dropped it on the ground between us. For a second, he started to reach for it, but my muzzle was already covering his face and he stopped, hand still outstretched. Time stood still for a couple of seconds as I made out the folding knife on the ground, the blade partially out, much like in the picture. He looked at me, and at my pistol, and at the knife.
"You want it? Go ahead and pick it up, Motherf--er!" I panted, all out of breath from the sprint.
"I don't want it," he said after a few seconds, slowly straightening up and raising his hands. I proned him out, got the cuffs on him, and was walking him back to my car when everyone else showed up. As it turned out, the car itself was stolen, and there was crack in the door pouch and a pistol under the seat.
But then we went to court, and the case went right out the window as he claimed that the car was loaned to him by "some guy in the neighborhood" (Hey, don't we all have a guy in the neighborhood who just lets people use his car?) and he didn't know that it was stolen. Since there was a key in the ignition, it went the way of all "key cases" in this sad excuse for a court and wound up dismissed. His public defender also argued that he didn't know that the drugs and gun were in the car, and predictably, those cases were dismissed, too since the prosecution could not prove otherwise. Since he'd never managed to draw the knife and threaten me with it, that wasn't even charged, so all he wound up with were a few traffic court charges for the pursuit.
All of the other evidence--the gun, drugs, and the license plate--were turned in for destruction as the knucklehead walked free, but I said that I'd be damned if he was getting the knife back and I kept it since it was a decent one and I needed a new one for work use. It's just a little Carolina lock blade, but it holds an edge and came in handy many times slicing seat belts, cutting a noose around a suicide victim's neck, and opening boxes and poking holes it the tops of coffee cup lids. I've had it for many years now and it's kind of a good luck charm now.