Most annoying things in video games

[Darkangel]

when I keep telling people "I can't heal you if you're out of range or if I'm moving" and they just rush into battle anyways.

Playing medic in a nutshell.

[Teal Turken]

When someone calls me a hacker just because of my skillz 

When someone bans/kicks you out of the match under the false claims of hacking.

I started playing the Mass Effect series recently.
The HORRIBLE AI teammates in Mass Effect one...
Stop standing there and help me!

[Dark Hooves]

When someone calls me a hacker just because of my skillz 

When someone bans/kicks you out of the match under the false claims of hacking.

I started playing the Mass Effect series recently.
The HORRIBLE AI teammates in Mass Effect one...
Stop standing there and help me!

I hear you buddy

[The Wandering Magus]

when I don't notice my own health bar going down to zero because I'm too busy trying to heal twenty other players screaming at me at once

[Nightmare702]

Taunt parties.

[The Wandering Magus]

rude team members

[Pipkin]

When someone calls me a hacker just because of my skillz 

When someone bans/kicks you out of the match under the false claims of hacking.

I already have 2 "hack demos" uploaded for Li'lDerpy and LaptopBrony, now it's time to work with DerpshyDashkie and see how long it takes to make it 3.

I hate setting up a skirmish for SFC3 because of my wanting a specific officer setup:
(Derpy Tactical, RD-Helm, Luna Security, Twilight Ops, Pinkie Pie-Engineering, Fluttershy Medical)
which can take anywhere from 1-6 minutes to do, and then I launch the game and forget to set the gametype and i'm playing base assault....

[The Wandering Magus]

actual hackers

[PrincessButton]

actual hackers

^^^^^^^^
They really ruin the fun for others. ><

[Tiger]

actual hackers

This. Especially someone on TF2 who plays Heavy and then speed-hacks to make him ridiculously fast 

[Julius]

actual hackers

I'm glad to say I haven't encountered many before, but when I do they are a major pain...

[Jenzy]

rude team members

It's not from speaking or typing rude, as there are set "Calls" in Luigi's Mansion: Dark Moon, but it's rather rude when someone goes "afk" (Well, away from the 3DS or just not participating) in ScareScraper.

Especially during a Boss Battle or Rush Mode!

One of the players just stood there, and we've already found the exit. Time was ticking. Collected Time Pieces, and one Luigi just stood in one spot.

And one time, I only reached the first boss of the ScareScraper in Endless (difficulty goes up slightly per floor) from the continuous spawning of other ghosts scaring Luigi and attacking him, while draining Boss HP. Requires teamwork to keep the ghosts away while battling the boss, and help decrease the HP faster. Virtually impossible on your own.

You could probably guess what happens next... GAME OVER! You ran out of time!

[Teal Turken]

actual hackers

This. Especially someone on TF2 who plays Heavy and then speed-hacks to make him ridiculously fast 

They're far worse on Arma 2 and 3.
Arma sorta lacks a good anti hack so quite often you'll get sudden deaths across the board and being spawned in the ocean or high up in the sky.
The worst is when you're spawned at base with about 300+ vehicles piled all over the place and they explode and continuously explode, sometimes it'll crash the server or even your client.

[Dark Hooves]

the dont throw grenades mod on the halo games

[The Wandering Magus]

when other team members spam the game chat with

MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!

[Teal Turken]

when other team members spam the game chat with

MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!
MEDIC!

Dispenser request spam...

[The Wandering Magus]

when you're two points short of being able to afford something and then the time runs out

[KoalaLover99]

When you're enemy escapes with 3HP

[Asterian Starfall]

When you have 99% Ubercharge and you die from a crit rocket.

[Dark Hooves]

sniper noobs