Top three calculators ?

[isanchez]

For me:
1) HP65: (it's strange no one has mentioned before). What a calculator! Its so elegant! Just hold it in your hand! (I do not understand why the HP67 was filled of instructions in the keyboard overlay).
2) HP15c: original design, power, reliable. A reference.
3)Hp41c: but the very early model with tall keys and metal keyboard overlay.

My selection is not based on capabilities...any of the free mobile apps provides you more power.

Thanks and kind regards

Ignacio