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.
Breville Milk Frother. Got one 10years ago. Really elevates your morning cup of coffee or tea and also great for putting on porridge. They’ve gotten ridiculously expensive though.