A big pile of cotton kitchen towels. They are good to wipe surfaces, food, dishes, hands, to cover dough to let it proof, or to grab hot pots with. They are reusable, and thus help to cut down on money spent on paper towels.
Stainless steel bowls. They are great for mixing ingredients in, for ice baths, stacking them for double boiler setup or improvised ice cream maker. And of course to serve things in.
Cut resistant gloves. They come in handy for using graters, mandolins, and when cutting large (and cold) pieces of meat. I am good with knife but had far too many close calls over years. If I am cutting a cold and unwieldy chunk of beef, I will put a glove on. Not only will it help avoid cuts but it also keeps my hand from getting cold from the meat.
Stainless steel wire rack for baking and cooling. I am surprised how many people live without one. Resting cookies on one is essential to make sure they come out perfect, and that's just a one example
Kitchen scale. It's a must if you are serious about baking and want consistent results every time. Same for brining. Measuring solids by volume is too unreliable in my experience and am glad to see that more and more recipes are listing ingredients in grams these days. It's great for portioning food and a must for tracking nutrition.
Small, skinny silicone spatulas. Great for scraping out jars, mixing delicate foods, getting into crevices of containers, helping to get muffins and other baked goods out of pans, agitating mustard and other things that can come in narrow jars that sometimes barely let a small spoon fit in.
Spider Skimmer. Very useful, from obvious uses like fishing food out of hot water or oil, to less obvious ones like separating eggs yolks from egg whites. It's much more versatile than slotted spoons and pasta spoons.
Dough scraper with a ruler on it. It can be used to easily slide chopped food off of cutting board, to measure the thickness of fish filet or parchment paper, to work with dough, to portion foods, transfer ingredients, and more.
Potato peeler with a blade perpendicular to a handle. It makes peeing faster than parallel ones. Besides peeling, it can be used to make thin slices of vegetables for garnish, to peel hard cheeses, get rid off discoloration from veggies, and more.
Fish spatula. Besides cooking fish, it's also good for helping to fold omelettes, flip pancakes,
