"Prometheus swept down from the heavens bringing the gift of fire. Wrong move." Robert Ludlum

I found this topic on GameFaqs made by Aeroguy24, "10 Things That Piss Me Off In Game" (Referring to Halo 2 online). Enjoy!
12-year-olds
These people are capable of shattering glass with their high pitched voices. They are the self proclaimed "bad asses" of Xbox Live.

"l33t Players
These are the people that speak in anagrams. They belt out such phrases as "OMG h4xors!" while playing.

Serious Players
Serious Players cannot lose at all. If they begin falling behind they scream at their team to pick up the pace. They fail to realize that this is only a game and winning isn't everything.

One Man Warthog
One of my personal favorites. Many times you will often see this person bolting away from the spawn point at the beginning of the game. Never do they allow a gunner, because that would be slow and practical. Instead, they'd rather just rush the rocket spawn so maybe they will have a chance at killing the tank that will blow them up.

Rocket Whores
We must all realize that the rocket is indeed a powerful weapon and should be used when given the chance. But screaming into your mic that you are God when wielding a rocket launcher is just plain wrong.

Noob Combo-ers
I have no problem with the plasma pistol being used as how its made, but it really pisses me off when people worship it. Give it a break every once in a while and try out that sniper.

Bad Warthog Drivers
Some people were never meant to drive. They go as fast as they can and hit a ramp sideways. Their driving severely messes up the gunner and passenger, not to mention most of the time they will be thrown form the hog and left to deal with the enemy.

Team Killers
What are you trying to prove? Killing your team just so they lose is pointless in every aspect. Try enjoying the game instead of making everyone else hate you.

Smack Talking
This has become a kind of legend among the gaming community. People on any system hear of how bad smack talking in Halo 2 is. Most of the people who smack talk don't even deserve to. Unless you're getting 50 out od 100 kills in a BTB match, then shut up. It looks real stupid when you call some one the "N" word then got shot in the head that very next second.

Free-For-All Team Battles
That word team doesn't just mean what color you'll be, it's also those people that are that color as well. You're given up to 8 people to fight beside you, use them! Every team battle turns into a free-for-all where you can only kill people of different colors (not a racist remark). Team work saves games. Those who chat are those who win.

Well those all of mine. Comment, disagree, or post your own. Im sure there are a lot more things that piss you off in Halo 2.