"Go together" is a common phrase that can be used to describe two things that complement each other, or two people who have a good relationship. However, there are a number of synonyms that can be used to convey the same meaning. Some examples include "fit in," "mesh well," "harmonize," "complement," and "match up." Another option is "click," which can describe two people who get along well and enjoy spending time together. No matter which synonym you choose, the overall message remains the same: these two things or people work well together and are a good match.