The Instant Pot and the air fryer. I thought they were both just dumb gimmicks until I got them both for free, and now I use one or both of them pretty much every day!
I’m still in favor of awarding a Nobel Peace Prize to whoever invented them. The ammount of people I didn’t have to strangle in the train after work is immense
Mine was a Scrub Daddy. I had heard about them for years. Thought that "there's no way a dish sponge can be that good," plus no stores around me carried them and I'd be damned to put an online order for a single pack of dish sponges.
I was out a few weeks ago and saw that my local grocer has started stocking them and decided to pick up a pack. Holy shit these are some good sponges.
Japanese knives. We're so accustomed to 15$ kitchen knives that it seems ridiculous to spend 300$ on one, but man, it's amazing. You definitely need to learn some knife etiquette (Japanese knives are harder and brittle) and how to sharpen them but once you do, it's amazing.
They are designed to be extremely thin as to slice through ingredients easily and extremely hard to maintain razor sharpness.
If you do buy one, you will probably want stainless for your first one, and AVOID AMAZON. All of the Japanese knives there are completely fake and made in china. I would instead do lots of research and support independent blacksmiths. It's expensive but most blacksmiths make very little and work out of pride, passion and dedication for their craft.
Replacement is very easy, just screw the old one out and the new one in. Refills are under 7€ around here and they last for quite a while (they claim 60 L per canister but I've never really tracked how long they actually last).
You can theoretically also get an adapter kit to either refill with your own big CO2 canister or directly connect a larger canister. Unless you are a very heavy user this is probably not worth it though.
Regarding brands, I don't think that there's a big difference between sodastream and off-brand ones. The cylinders are typically interchangeable as well (as long as you don't get the "quick connect" ones from Sodastream). I would also recommend getting a model with glass bottles instead of plastic ones because you can put them in the dishwasher.
My dad has a soda stream, and I have his old one. He refills our canisters with dry ice. I like just plain fizzy water (him too). I don't think the "soda drops" ever really got close to regular soda, but for plain carbonated water it's fantastic