I don’t just mean a wrench, unless thats it for you. I mean any tool you regularly use for work that you consider your most important. If you’re a software person name whatever digital tool you guys use. Whatever the career everyone uses tools I dont care if they are digital, verbal, physical or psychological. For me its honestly probably a flashlight, before I use any tools I’m always investigating with my flashlight or using a laser to trace lines.
I think the knipex pliers wrench is my single favorite hand tool, it can really do anything that involves screwing or unscrewing with so much ease
I have one of those too and it’s pretty great for chrome plated plumbing parts because it doesn’t damage them but cobras can do everything those can and more so I just find them more versatile.