Part of it was Gerard Butler, whom I loved in Reign of Fire (2002; he was a lot less beefy then) and in Beowulf and Grendel (2005). And part of it was Lena Headey as Queen Gorgo. And a whole lot of it was Rodrigo Santoro as Xerxes.
And, of course, I do see how people could watch this film and read into it some hawkish parallel with the various U.S. wars being waged against the Middle East. Hell, I wouldn't be surprised if the frelling U.S. military wants to use 300 as a recruiting film. But, surely, surely...only an idiot is going to buy America in 2007 CE as Sparta in 480 BCE, or see the U.S.'s "shock and awe" high-tech invasion of Iraq as some equivalent of Leonidas' stand at the Battle of Thermopylae. But, yeah, I know. Idiots do abound.
I will say, though, that I think the battle scenes in 300 still are not as amazing as the battles in Jackson's The Two Towers and The Return of the King. But, nonetheless, I did like this film.