Top three calculators ?

[Postfix]

These days my favorites are:

1) HP12C (the original as well as the Platinum model, mainly for simple everyday calculations and for recreational programming)

2) HP32sII (IMHO the sweat spot of all scientific RPN models, and its keyboard is so much better than any of the SM clones)

3) Casio fx-3650PII (reliable keys, but definitely not a dedicated engineering tool, nevertheless programming is fun, and it has logic functions missing on the HP32sII)

Position 3 changes regularly, but 1 and 2 have been fairly consistent over the last 10 years. All serious numeric work is done on the computer. In the past this was partially the task of a Casio fx-850P (expanded to 32 kB) and an HP48G. The latter still resides in the drawer in case the other calculators fail.

Regards,
Thorsten