Bungie's "Bye" was a very good one. This is the best Halo game that has been made.
They made it as a "bye" to all the fans and gamers, which is another reason it became the best.
Why it became the best was because of the HUGE content in the game.
It has many multiplayer VS modes, the creative forge mode for building your own bases, flying around or just messing with things.
The campaign starts with a bad storyline, but when you get to the end you understand what the game is about and makes the storyline much better too. There is the Firefight game mode in this game too, where you fight together in teams against waves of covenant. There are all the old game modes included from the old games, and some new ones that I haven't seen in the old games like Mongoose racing, infection and more. There are many weapons in the game, including the needler, assault rifle, sniper and the DMR and a "joke" weapon that works like the Gravity Hammer.
The game mode "Forge" is the best in my opinion, there you can build anything on a map, like a sniper position, a swimming pool, a landing pad or you can just explore a world with your best buddy in a falcon. There are also many stunts you can do with the mongoose or warthog, which is quite fun when I do it.
The graphics are very good and makes the game look beautiful. And since it's a "bye" to all the fans, they added alot of easter eggs in it too, but I won't spoil them for you. You can find them yourself, or use your old friend Google.
Sadly, they didn't add flood and there wasn't a 4-player splitscreen co-op mode.
Shortly said, it has HUGE content, fun easter eggs, good graphics, good storyline and is one of the best Xbox 360 games made, but doesn't include the alien zombie guys that made me think all the first 3 halo games were interesting..