Promise you this isn't clickbait or some kind of a joke. I'm 100% serious. The series is far greater than Ridley Scott's Gladiator.

 Fate/Zero is an anime based on the light novel by Gen Urobuchi and it's directed by Ei Aoki. If you are already familiar with Gen Urobuchi you don't need me to recommend anything. You've probably even watched Fate/Zero or planning to watch it. For those who don't know Gen Urobuchi just think of him as a great deconstructer. Ei Aoki also directed  ΛLDNOΛH.ZERO which is another great piece of work. But Fate/Zero in my opinion is even greater than  ΛLDNOΛH.ZERO 

The anime is actually a prequel to Fate/Stay Night which started out as a visual novel. In japan the narratives of top level visual novels are better than feature length award winning movies in the west. Fate franchise is a proof of that. If you haven't tried any anime Fate/Zero can be a great introduction into the genre. 

The series has 25 episodes filled with exhilarating battle, philosophy, somewhat psychologically disturbing content and the series isn't really a one that pulls its punches. It can devastate its characters ideology and beliefs in ways that rip their souls apart. Nothing is sugar coated. But unlike some of Urobuchi's work the darkness and violence is very restrained and used sparingly but impactfully.

The series explores and makes you raise questions about god & evil, nature of kings, justice, utilitarianism, aristocracy, power, sacrifice, hopes and all in high production quality animation. When the series came out, it simply had the best animation in a series. Period. 

Fate is growing to become a massive franchise. So here is something that might come in handy for you: