Best potentiometer value to buy

Croutonix:
I have the choice between buying 15 potentiometers with a 10k value.
Or I can buy 15 potentiometers with 15 different values.
I want to use them to fade light, choose item in list (on LCD), adjust volume, etc.
Do potentiometer values matter a lot or any will do?

Will you be reading the pots from software everytime, or using them directly in
circuits??