Back in the late 90s, when TI already ruled calculators in High Schools, I selected HP48 as my platform. It is a high-end engineering calculator with CAS capabilities, native units, stack based interface and programmable in RPL.
Recently I purchased a near mint HP48G and again have a physical calculator on my desk.
Between rich library, various symbolic solvers and even ... more on:

HP48 Again
Back in the late 90s, when TI already ruled calculators in High Schools, I selected HP48 as my platform. It is a high-end engineering calculator with CAS capabilities, native units, stack based interface and programmable in RPL1. Recently I purchased a near mint HP48G and again have a physical calculator on my desk.