What kind of salt makes the best bath salts?

Most of the recipes I've found call for sea salt or epsom salt. Which are better? Can I use any other salt like rock salt?What kind of salt makes the best bath salts?
i actually make a sell bath salts, i use a mixture bewteen sea and epsom salts.... more of the salt then epsom.... i also put soap fragrance like lavender which you can get at a craft store and mix it with actual lavender buds :) smells great :)What kind of salt makes the best bath salts?
Epsom Salts
sea salt
Sea salt works if you are making a scrub. If you are just making a bath salt to soak, epsom salt is the best bet.