We sometimes take one of our cats with us, but only if we're going somewhere where she won't be shut up alone in a strange place for any length of time. Each of the cats seem to enjoy spending some alone time with us, when they don't have to compete for attention.
Otherwise, we leave them at home. If we are just going to be gone overnight, I add and extra couple of litter boxes and make sure they'll have enough food and water. If we have to be away for longer than that, we have a friend come in and change the litter boxes out, and make sure they have fresh water and food. Since she doesn't like dealing with cat litter, I keep some extra cat litter boxes around and fill them for her ahead of time, letting her just dump the others into a plastic bag in our shed, for me to deal with when we return.
I try very hard to avoid being away for long because two of my cats are twenty-four and, although they're healthy, I don't want them to have spend any more time than they have to alone or uncomfortable.