I'd definitely have to go with my CRKT Nirk Tighe. The original Nirk was designed by Glenn Klecker, which caught Brian Tighe's eye, eventually leading to Tighe modifying the Nirk, making a completely awesome and innovative knife. The whole idea behind the Nirk is a knife with the least amount of seperate parts possible (some are just two pieces of metal!) that works as a functional lock-back folder. You have to check it our for yourself, because there's no way that I can explain how much genius went into this beautiful factory folder with a custom look to it. It's also the only lock-back that I know of that features a flipper-style opening; and a smooth one at that! Basically, it works like a see-saw. The handle (which for the Nirk is one piece of steel, the Nirk Tighe is actually held together with pins but still delivers the same effect) has specific cuts, and is made from a spring steel, to make it act like a lock-back. What you may first think is that it would be easy for the lock to slip open when you grasp it tightly, but when you hold the knife you're also pressing your hand against the entire lock bar portion of the handle, which is so effective that mine has never opened up in my hand before when I hold it. Although it does take some getting used to. The entire inside portion of the knife is dyed blue with some titanium alloy or something (I'm a little foggy with the details) but ends up looking really nice, which is an added bonus!