I'm watching 300 again (but properly this time, from start to finish), and I can't make up my mind about whether I like it or not.
On one hand, it's wonderfully faithful to the graphic novel source material. It's great to look at, and it's a visual masterpiece. And, of course, it's one of history's greatest stories, well worth telling (even though they did make a lot of stuff up).
On the other hand, it takes itself way, way too seriously.