For me, it’s an electric toothbrush. It doesn’t matter if you go with Sonicare or Oral-B, once you start using an electric toothbrush, regular toothbrushes don’t ever feel like they clean your teeth properly. The smooth plaque-free top layer of your teeth that you can feel after using an electric toothbrush can’t be replicated with a regular toothbrush.
This is kind of cheesy probably but I upgraded to the Pixel 9 Pro XL and added on the Pixel Watch 3 (45mm), as well as the Pixel Buds Pro 2 earbuds the year before last. I had exclusively used cheap budget Android phones and wired earbuds before. I did already have a Samsung Watch 5 but I got the Pixel Watch 3 for the total current generation ecosystem experience at the time. It is so much more elevated than my scene prior to that. The Pro 2 earbuds are fricking phenomenal. I sleep with them every single night without any discomfort whatsoever and both buds are still in my ears when I wake up virtually every day. Anyway, I was shocked at how much more pleasurable it made my interaction with personal tech. I will likely never spring for all new gadgets again but I will continue to buy the flagship level devices from now on, even if I’m buying them a couple of years old on Swappa.