When it comes to describing something that is very popular, you want to use words that convey just how widely beloved or appreciated it is. Some synonyms for "very popular" include trendy, sought-after, hot, in-demand, renowned, celebrated, and beloved. Other words that could be used to describe popular things might include classic, timeless, iconic, ubiquitous, mainstream, or widespread. Depending on the context in which you are using the phrase, you might also consider other words that help to underscore the enthusiasm or adoration that people feel for something, such as fan-favorite, cult classic, or runaway hit. Ultimately, the best synonym to use will depend on the specific thing you are describing, as well as the audience you are addressing.