What Hand Soap do you guys use?

Depends what i'm working on.

For dirt or light grease - dawn
Heavier grease - I will use fast orange or similar citrus/ pumice cleaner
For worst messes, paint, epoxy, bondo, ink... Stoko Cupran Special. A bit pricey, but it takes off damn near anything and not harsh at all on hands.

Edit - Just looking this up and I see they are renaming it. Still shows Cupran, but new label is KRESTO ATP (adhesive, tar and paint remover)