Leatherman Wave. It is a tad big for every day carry but it is great for camping or walking in the woods. I can use it to cut those wild grape vines strangling my black walnut trees, or to tighten the electric fence wires, or to unscrew a pesky battery connection on the mower, or….
For every day I have a much smaller Leatherman C303 . It fits nicely inside my belt or in a pocket. (I see that it is no longer made and has been replaced by a newer model.) I particularly like the “Blade Launch” system – a small lever mounted near the blade.. You can easily open it one handed even while wearing gloves. (Spring loaded switch blades are illegal here.) I can hold the vine with one hand, whip out the knife and cut it in seconds. The serrated edge section is about 2 cm long and is perfect for a quick cut of a vine. That is much easier than carrying lopping shears with me all the time.
I keep a cheap multi-tool in the glove box of all my cars. Usually you can pick them up for few dollars at GoodWill or garage sales. I don’t care if they are rusty or if one of the blades is missing. It is far better to have something than not.