I know Halo 3 is getting a little old now, but it's a game I still play and thoroughly enjoy online. Although there are a few things I really think Bungie needs to fix in some of the maps

First of all I can never understand the 'spiker', it's very inconsistent, sometimes it deals just as much damage as the Assault Rifle (able to kill in one clip) while for some reason Dual Wielding it doesn't seem to deal any extra damage even though you're pumping twice as many bullets into them. The same goes for the SMG. Overall it doesn't seem like there's much of a point in dual wielding weapons at all unless you're using the plasma rifle and a spiker/smg

Another thing I can't stand about playlists that involve attaining a score by killing other players is the vehicles. Time and time again on a team game I'v seen someone score at least about 3 or 4 kills with ease because they picked up the Ghost and started running people down. I can understand the need for vehicles on objective based maps however.

Another thing I can't stand is the Rocket Launcher, and because of it I absolutely loathe playing The Pit or any other maps which have it. Not only can any inexperienced player score at least 3+ kills out of it with ease, it grossly outclasses every other weapon out there. In my opinion the Missile Pod is a much more balanced weapon, it's difficult to use, has a very small blast radius, but will still kill on a direct hit.

Finally, there isn't much more annoying than bashing someone at the same time they bash you after you've emptied a whole clip into them and for some reason they miraculously survive. It's probably lag but I really can't stand the strength of the melee attack, especially the ridiculous distance some people will lunge when doing a melee attack.

Well that's my little opinion :p