One. If you have a penis and balls, go see this movie. If you have ever enjoyed or had fun watching an action movie featuring swords, go see this movie. If you like naked women, hell, go see this movie.
Two. I am not gonna explain the historical stuff. If you're a goddamn retard and didn't pay attention in history class and don't know about the battle of Thermopylae then go google it or ask your tard herder or something.
Three. Review time i guess.

300 is a man's action movie. Based on the Graphic novel "300" by Frank Miller, it features all the sex, violence, more violence, slow motion, lesbians, mutant hunchbacks, slow motion violent lesbians touching mutant hunchbacks etc a man could ask for. Storywise, it's a very imaginative retelling of the battle of Thermopylae, and, in this movie, this translates to 300 spartans and some pussy ass other greeks holding off like 400,000 goddamn crazy ass slave taking freaky Persians. What this translates to on screen is some of the most (some would say OVER-) styleized and amazing looking action scenes you will ever see in a movie. The graphic style is basically, well, a video game combined with oil paints combined with CG combined with real people, and it looks goddamn amazing. Blood splatters, people fly, the actions fast forwards and slows down in alternating awesomesauce, and holy hell, does it make for an amazing action experience.
Other than the action, well, there's not that much to it, and in all honesty, though the story is there, nobody is going to this movie to see the story (if you are, see #2, you retard), but the story that is there is pretty well done. Every line in the movie is overacted, but it just fits so damn well with everything else about it. It's like the perfect puzzle or some analogy i can't make because i'm dumb. And did i mention naked women? All you basement dwelling neckbeards that frequent this forum will probably want to go just for this, but you know what, that's fine, maybe you'll become more manly from watching it.
To sum it up. Go see this movie, and if you don't think it's an awesome action movie (if nothing else) then GTFO.
Peace
PS: BLIZZARD, GET YOUR SERVERS UP. GAWD.