This film is a masterpiece in many ways.
Very well written. The acting is top-notch, especially Russell Crowe and Joaquin Phoenix. The lighting is perfect. Cinematography is good. And the character of Maximus and a lot of the imagery are what make this movie.
Obviously it is historically inaccurate, but it doesn't actually bother me. I know what's inaccurate and simply don't think of it as a historical movie with a bunch of flaws, rather a fictional story with a bunch of true facts thrown in.
My only problems are the kiss (which takes away from Maximus's devotion) and the paganism.
Containing some of the most powerful imagery I've ever seen in a film, it also has a beautiful ending. If you can put up with the violence and blood that earn the R, I recommend it.
Certainly deserves it's 5 Academy Awards...