Given how slow my CASIO PB-700 was at plotting graphs, around age 8, my parents upgraded me to the Sharp EL-9400 (manual).
It was a big step up for math, but barely programmable. I wanted a fast BASIC playground.
After a lot of starring in stores and begging, I received the dream machine: the TI-92 Plus (manual). It was a TI-89 in the body of a TI-92. Fantastic machine to code in BASIC and, as I discovered after breaking an arm, take notes in class.
Came with a powerful Symbolic Algebraic System and Cabri Géomètre (a brilliant app to construct geometry). Once I discovered how to transfer files from the Internet onto it, a lot of games followed.
It lasted quite a few years. When it finally gave up, I immediately replaced it with its successor, the TI Voyage 200 (manual), which I've kept to this day.
Smaller form factor but AAA batteries instead of AA, double the flash, a really minor revision.
In my adult life, having lost interest in calculators for anything but quick calculations on the go, and having embraced RPN to the point of implementing a postfix language for fun, I've acquired a HP Prime (manual).
Sadly, I don't care to get past the home screen anymore.