The Renaissance is basically "hey, remember Rome?", our laws today base themselves around their laws, they created the first western instance of a republic AND the first nation-state (after they made citizenship universal on the empire) along with the bureaucratic means of administering empires, their roads last to this day, the knowledge they spread still influences us and if it wasn't for them you would have a pretty good chance of speaking a celtic language. They also spread Christianity so there's that. Their military order was mimicked thousands of years after that and some things (like concrete, our calendar and the first codex) were invented inside the empire, and their most incredible leaders are to this day seem as some form of inspiration, while the worst of them are seem as warnings from history. To this day people are fascinated by Rome and a lot of wealth was made solely due to the movies about this ancient empire.