I think that Halo games are one of the best games that have been created. The Halo universe is so unique and the characters really come to life. If you look at Master chief you will see a hero. In all parts of the game he is the main character and the hero. At the end of Halo 2 you think he dies, but even then he survives. In part 3 he comes back to life to end the fight and to save the world once again. In Halo 3 Orbital Drop Ship Trooper he is not the hero, but that is why the gameplay is different. You do not play as the marine, but instead as a orbital drop ship trooper. In the upcoming game Halo Reach Master chief will not be the hero, but instead there 5 other Spartans who have to save the world.
If you take a look at Halo 1 you will see something very new that we have not experienced before. The characters, vehicles, weapons and planets were all new. No one had heard of them before, except if you read the books which are great too. I do not know how many books there are, but I want to read them all. If think that if you play the games and read the books you know everything about the Halo universe. I hope they continue creating Halo games.
I forgot to mention Halo Wars. This is a game that takes place between Halo 1 and Halo 2. The gameplay is different again, because all the other games were first person shooters and Halo Wars is a strategy game. In my opinion Halo Wars was the worst game in the Halo Franchise. The controls were easy, but the gameplay was pretty dull. Halo is a first person shooting game and it should stay that way!