A Mat and Frame (mine was under $10)
A stamp pad
Have everyone in the family ink up their hands, then stamp them on the mat. If you're family is smaller than mine, have them stamp multiple times....if they're bigger use 2 colors of ink, and overlap the hands.
I like the stamps better than paint because it shows all the prints. The little ones are tricky, you may need help! Have fun, and don't forget to make one for yourself (I did!)