My favorite is the Crayola Ultra Clean Crayon set. I just started using them recently. I saw them on sale for back-to-school and decided to try them. I used every color heavily on a piece of white cotton and washed it in cold water. Every single color disappeared. I hear that people like the markers too, but I like being able to see how much is left. Also, with a wide range of colors, you have something that can be seen on every color fabric.
Tate