A 4-in-1 screwdriver. It will likely cover at least 90% of your lifetime screwdriver needs.
FileMaker Pro.
If I could only have one piece of commercial software and have to use it for everything, it would be FileMaker Pro. Admittedly it would make a lousy standin for Photoshop or Final Cut Pro or 3D rendering package, but it does a tolerable job for word processor, spreadsheet, web browser, scheduler, MP3 player, invoicer, input signal processor, home automation system controller, and general sketchpad for whatever ideas you may have floating around.
If you’re getting parchment paper, which you should if you do any baking/roasting/etc, do yourself a HUGE favor and get it in the 16"x24" size on Amazon. Comes in flat sheets that aren’t curled, will fully line a half-sheet pan up the sides (trim any excess), and cones, in a long flat box that can be squeezed in anywhere.
One of these under-cabinet jar opener thingies. It’s just a simple angle of metal teeth that are attached to a frame which is screwed into the underside of the kitchen cabinets. They cost very little and are an absolute game changer. Anything at all can be opened with a gentle flick of the wrist, from a soda bottle to a wide mouth CostCo jar I can barely get my hand around. I can’t believe I went so long without one.
The other day I had a coke bottle where the safety ring had not been perforated like it’s supposed to be. I didn’t even notice until I tried to put it back on. Tearing through the plastic was just that easy.
Mine has metal on both sides, but otherwise is much like this one.
Could have done without the undead anorexic spokesperson.
I know, right? And maybe comb your hair before you turn on the camera? LOL! But it was the best view of the gadget I could find without a long search. 
Fair enough. I was so horrified by the gauntness and pallor I didn’t even notice her hair.
My Wife bought me one for x-mas. I thought it a bit odd. But I use it nearly every night for the last decade or so.
Indoor/Outdoor thermometers. I’m kicking myself for not getting one years ago. We now have two. One receiver downstairs, one upstairs (currently 66f in my office, 0f outside. Low last night was -1 high was 20).
And for you note takers? Get a tablet. I have an Android S9+. I used to have ~4 notebooks (work, home, finance etc). It may be a bit expensive for the tone of this thread though.
Now I have everything organized into 12 folders on my tablet. I much prefer taking my work notes etc. by hand then typing them in. I used to think tablets where dumb to be honest, but it turned out incredibly useful for me, and I only just take notes on the thing.
A handmade comb. They are not that expensive and are really a significant upgrade to the scratchy plastic ones.
Is scrub daddy also known as the magic eraser aka melamine sponge?
I took one to my kitchen ceiling, it was like magic.
My contribution is the squatty potty.
I have a handheld version of that made by Oxo, and I agree, those things are indispensable. Some vacuum-sealed jars pop open quite easily by hand, but some are virtually impossible to open without this kind of tool, leading one to ask “what were they thinking?”.
I’m not sure which version of the tool would give you the most leverage, but the handheld version doesn’t need to be attached to anything and it’s never let me down.
Candle warmer! I love candles, I know there are a lot of people that hate scents, but I’m not one of them. The candle warmer is a small goose-neck lamp with a place to set your candle under the light bulb. The heat from the light bulb melts the wax and emits the fragrance. No open flames. Mine has a timer so I don’t even have to remember to turn it off.
I have about a bazillion screwdrivers but I totally agree with this. I have one screwdriver with a heavy resin handle that has a grip like no other. It has a shaft that can be pulled out and reversed for a different screw bit. The entire assembly can be pulled out to reveal another shaft with two more screw bits. So, exactly your 4-in-1. And it really does do at least 90% of jobs, and has such a great solid feel and grip that it’s always my preferred screwdriver. A real treasure in my toolkit that I’ve had for many years.
Everyone, get yourself one of these thingies. It changed my life!
Before this, I was having to take my glasses off and put them on fifty times a day in the course of my job. Now I can function like a nearly normal person. It’s pretty too.
Most 4-in-1 screwdrivers have relatively short blades. With the result the handle is in the way of any structure near the screw head.
Sometimes a stubby driver with a short handle and a short blade is the best / only fit for the job. Most times a full length handle with a full length blade is best. Only very rarely is a full length extra-fat handle with a shortish to stubby blade a good fit at all.
IME YMMV.
Scrub Daddy (and momma) are not the magic eraser, white things. Which I like too.
I like sudsy cleaning.
The scrub daddy is good for this.
It feels hard til you wet it. Then it is an odd feeling sponge. Takes getting used to.
I just love them. The 
shape is neat.
moisture wicking socks
I just realised I HAVE one of these (actually, I have several - they were supplied as glass weights to use in jars for making fermented pickles, but they are glass domes and they function as lenses). I should just slip one in my pocket when I go shopping. I know my eyes are getting old now, but I swear they are also printing the ingredient panels smaller and in lower contrast than they used to.
Lol! I keep one in the bedroom and one discreetly hidden in the living room, and if I could keep one at work, I would!
My, the things we Dopers can get into arguments about!
But here’s the thing. At a glance, this screwdriver looks like … a screwdriver. Not one with a short shaft, or a long shaft, or an exceptionally long handle, just a screwdriver. It’s only when you pick it up that you appreciate the perfect fit and feel of the handle, and only on closer examination does one see that it has interchangeable bits.
I’ve had this thing for maybe 25 years or more and it’s usually the perfect tool for whatever I need a screwdriver for, unless I’m working with unusual screw types. It’s intended to be general-purpose, and that’s exactly what it does – superbly. It’s only a screwdriver, but it’s just one of those little things – like my Pilot G-2 07 ballpoint pens – that are just so perfect that they’re a pleasure to use!