Which programs do you actually use in your calculator?

[cjmcc]

For my HP-15C, the standard programs have been:
1) Decimal -> Base
2) Base -> Decimal
3) TVM - Present Value Annuity Factor
4) TVM - Payment -> loan amount
5) TVM - Loan amount -> payment
6) Great circle distance
7) Great circle initial bearing

My HP-50g has lots installed, but the most frequently used is Freecell.