Best-seller is a term commonly used to describe a book, movie, or other piece of media that is extremely popular and sells very well. Sometimes, however, you may wish to use a different term to describe the same idea. Some synonyms for best-seller include hit, chart-topper, top-seller, runaway success, blockbuster, sensation, and crowd-pleaser. Each of these words contains a slightly different nuance or connotation, so you may want to choose the one that best fits the context in which you are speaking or writing. Regardless of the specific term you use, the meaning will be the same: something that is selling very well and widely enjoyed by audiences.