Out of the top of my head:
* LASIK. That's not recent, I had it in 2014, but it's still the best few thousands dollars I've spent in my entire life. I do need to wear contacts again in one eye when driving or watching TV, but I still marvel at waking up and seeing what's around me.
* My two robot vacuums. Yes, two. I loved the first one so much that I bought another one for upstairs. They work amazingly well and they are my two best friends in the world.
* Aftershokz headphones. They solved all my headphone problems. I still wear in-ear buds when I go to the gym or when I'm in a plane, and really want to tune out exterior noises (and gym music, gah), and every time I do, I remember why I love my Aftershokz so much.
* Yoghourt machine. I don't like most of the yoghourts I find in the US (although they're much better than they used to be), or they cost a fortune, and this little $40 machine makes them just like back home for almost nothing. I can't survive without yoghourt.