Knives, I must have a drawerful of them. For years I carried a Swiss army knife, the one there in the center, for its Phillips screwdriver. They are unfortunately, quite poorly made, in spite of all the propaganda the Swiss put out. They usually wore out on an annual basis and the plastic on the sides is quite susceptible to a variety of solvents and melt. The big Swiss Army knife, found on the beach in Key West is regulated to Afrikaburn events, where it slices up ostrich meat cubes for omelets and the cork screw comes in rockingly handy for all that good wine. Aside from that it sits in the drawer. The big Gerber flip blade is a nice knife with some kind of wonder metal blade, a gift. Last time I used it was in the field in Borneo, where it came in handy with slicing up all the rope we used for rigging. However I am rarely stabbing or skinning anything on a regular basis. It keeps the Swiss army knives company. The Skeltool, I love it, never carry it, too big. and easy to lose the little bits.
So what do I carry day in and day out. The Leatherman Juice. Since fixing loose bits and pieces on the airplane, car, espresso machines what I normally do. It has all the necessary attachments, pliers scissors, wire strippers, Phillips, straight blades and a blade knife to open boxes. The only useless thing is the bottle opener, I don't drink beer. It fits in the pocket without the "gee are you happy to see me, or is that a multitool in your pocket?" thing going on. If I have to put it in a pouch on my belt, I will forget it, I am that kind of special idiot. That one is around 10 years old, outlasting 10 Swiss turds. I don't believe they make it anymore, but it may outlast me. Not pretty, no fancy wonder metal blades, just some tools that seem to be surprisingly well made. The knifey part of anything I have is usually just opening up boxes or removing packaging from something. Again, haven't stabbed, whittled or skinned anything for a while now. I just wish it had the tweezers, I still get splinters from pallets and the like.
These things are intensely personal focused on what you need to do. So your criteria will depend on what you actually do with them. Forget any tool that is TSA compliant. They will still stop you, pull it out and then finally declare (after huddling with at least three of them), "oh it is compliant." Wasting time.
