>Religion
Entirely Greek in origin. While the Romans did have their own distinctly native gods early on, they syncretized with Greek ones over the centuries and by the time of the empire, they had effectively just become the Greek ones under different names. The Aeneid itself is just a sequel to the Trojan War
>Architecture
Also entirely Greek in origin.
>Aqueducts
"Roman-style" Aqueducts were originally invented by the Assyrians around the 7th century BCE.
>Intellectuals and Philosophers
Almost all of them came from Greece, Anatolia, the Levant, and Egypt and all wrote their works in Greek.
>Christianity
Stems from Judaism and originally planned on maintaining most of Jewish law until Paul decided that you didn't need to mutilate your dick to join. The New Testament itself was originally written in Greek (the Latin version used by the Catholic Church is a translation of this original Greek version). Constantine the Great was half-Greek and half-Illyrian and was the one who moved the capital from the city of Rome to Constantinople. Many Church Fathers (Origen, Cyril, etc) came from the eastern half of the empire and wrote their works in Greek
>Gladiator tradition
Came from the Etruscans
The only things the Latins themselves excelled in was conquering shit. Even then, they started conscripting more non-Latins as they expanded. Their best emperors weren't even from central Italy (Trajan, Hadrian, Aurelian, Constantine, etc).