Great movie. I think it was a little over-hyped. The fight graphics kick ass, but for some reason no particular scene really stuck with me like some of the ones in LOTR or Braveheart or even Fight Club, I think cause there wasn't as much of a story... it was pretty much just a setup to have a bunch of guys kicking ass and taking names. That's still fun to watch, especially with such great graphics, but I liked Gladiator better. The lines are cooler when you've got a believable badass character behind them.
Example, in 300, the Persian says, "Our arrows will blot out the sun," and one of the Spartans says, "then we shall fight in the shade." That's cool but it doesn't give you the kind of chills you get when Maximus gives his coolest line in Gladiator, turning around to face the Emperor in the ring and saying, "My name is Maximus Decimus Meridius ... and I will have my vengeance, in this life or the next." You get more into it with more story behind the characters than just introducing them right from the start as ultra-badass super-warriors.
Still... great movie.