It's not the best game ever but it's still very solid with a great multiplayer to keep you coming back.
Graphics - 8.5/10 The graphics are up to the genre but Bungie could've done better here, still there are some sweet looking maps and explosions sure do look cool.
Sound - 9/10 I would say the last two games had better music but the games voice acting has improved and the theme remains probably my favourite still.
Story - 9/10 It's pretty much where it left off but it left off pretty damn well but the fight is finished the fight so... no more Halo.
Gameplay - 9/10 As good as ever, online play but it's finally starting to get a bit repetetive with same old shooting all over again.
Multiplay/ Replay -9.5/10 I know COD4 has got more popular recently but if you've not played Halo 3 online, do yourself a favour and get the hell on there. There's the usually difficulties, the meta game and co-op to keep replay alive
Overall - 9.2/10 This is my average score but I think on overall it deserves a 9.5 because it kept the game fun and alive with a better solo campaign and Bungies ability to keep the multiplayer so sharp even today.