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.
I wanted to punch someone when i realized my Bosch drill and Bosch electric saw use different batteries. They’re identical in size, but the plug part on one is a mirror image of the other and so not interchangeable