Having played the original Halo and Halo 2 and loving them, Halo 3 is my favorite. Other Halo games in the series pale in comparison. If the only games you've played are ODST and/or Reach, you may love this game. There are very few brand new abilities that make this game's campaign worth a second go. I finished the game in 3 days. Got a message saying thanks for playing the campaign and that there's new play styles online and challenges. All I could do is sigh and say enough is enough. I prefer the freeplay style of Borderlands even though that is getting boring too. Having to run through Halo with constantly having to interrupt the battles to search for alternative weapons and ammo gets tedious and breaks up the gameplay so much so, it's no longer fun. I may pick up a copy in a year or so when it's $20 new, not worth $60 new.
this game brings a new look to the halo franchise with stunning graphics you will never get tired of and a campaign that is deeper than any other halo game i have played. the multiplayer is tons of fun with the new spartan ops that allows any halo player to never be bored of the game anyone who wants to play a REAL halo game should really pick this up.
If Reach Multplayer let you down a bit, or a lot, it is time to come back. Halo 4 is incredible and a triumph. The action is intense, varied, and fast. 343 Studios has taken Bungie's recipe and created a real gem.