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.
Stick blender! I delayed buying one because I thought the regular blender I had was enough, but this one is so convenient for sauces and soups.
e-reader: another item I delayed buying for too long because I believed paper books were better. I bought a Kobo and ended up reading more often.
I can FLY on an eReader. I bump the font up a bunch and just go, baby. Love reading ebooks (i read them on an ipad mini). I was also Mr. Physical Books Forever. Boy was I wrong about that.