It was a spectacle, certainly. However, I wasn't moved by the story, didn't care about a single character, and thought Commodus was a lame duck villain.
I thought 300 was a lot more successful in what it was trying to do. My expectations were a lot lower, I definitely didn't care about the historical inaccuracies, and I had a fantastic time. Gladiator left me flat. Nothing really happened, and the things that did happen didn't really move me. This is coming from a guy that LOVES revenge films. Problem was, it was Commodus, and I simply didn't care at all about him.
Also, for what it's worth, as completely unbelievable as they were, the combat scenes in 300 were much more exciting.