Great all around game!
The campaign in this game is highly addictive, action packed, and the graphics are nothing short of incredible. Not to mention the option of 4-player online co-op which makes the campaign always fun to play.
The multiplayer in this game is large and indepth. There is a wide variety of maps and game types, along with ranked and social playlists so you can choose if you want to go hardcore, or just play casually. Another big thing about online multiplayer in Halo 3 is the incredible advanced stats system set up on bungie.com where you can see just about every stat you can imagine.
The only thing i find wrong about this game is that they come of with a lot of map packs that you have to pay around 10 dollars for and if you don't buy them it affects what game types you are aloud to play. Other than that it is a very fun game and i'd advise any of my friends to buy it and give it a try.