Inspired by this post here are some things I consider to be good. I'm not providing links, you can find your own suppliers with your choice of search engine. I'm calling this the 2020 edition because I've not bought anything in 2021 yet.
MSG: Augment food with a pinch of umami.
Aeropress: Mine is approaching ten years old and is still fantastic. Makes the best individual cup of coffee without doing loads more work.
Grinder: Specifically the De'Longhi KG79. It's not the perfect grinder but it's damn good for under £50.
Rice steamer: If you don't have space for a proper rice cooker this one you whack in the microwave is perfect. Mine is from Sistema.
Cleaver: For £13 the Kom Kom knife is incredible. It holds a sharp edge for a decent amount of time and just feels good in my hand.
Knife sharpener: Pair your Kom Kom with an easy knife sharpener. Ceramic wheels give a good enough edge with basically no effort. I can't find mine for sale any more but other similar ones exist.
Phillips One Blade: This was recommended by Sean on Midnight Resistance years ago. It's not the closest shave you'll ever get but it's good and works wet or dry and importantly is really gentle on my skin.
Uniqlo Airism boxers: These come recommended from Sayem and are very comfortable and a godsend in warm weather.
Door Bell: You can get not-shit doorbells for £15 that are wireless and don't require any drilling. Mine are from a company called Avantek but they're just rebadged stuff from China.
ANT+ Dongle: If you do virtual bike rides on things like Zwift but get frustrated by Bluetooth being shit, get a dongle for your PC. ANT+ pairs with my trainer and sensors in ~5 seconds. No photo because it's just a slimline dongle.
Outside lights: Battery powered and motion sensitive outdoor lights. They can be applied to surfaces with sticky pads but I drilled into brick/wood for them. Batteries last ages. Mine are from Proxinova but similar brands are available.
Food waste caddy: A bit more bougie but the Joseph Joseph Food Waste Caddy and compostable bags are great. The weird venting means there are no bad odour. Collect your compostable food waste and put it in a composter outside.
Dishrack: Again from JJ but these are brilliant. You can really extend the amount of drying space on sink with these.
Hooks: Sticky backed hooks are great for quickly adding some extra storage. I mostly use mine as hooks for headphones at my desk or on the side of my bedside table.