Yes. I was playing RTCW on Xbox Live after it just came out (before Halo 2, this was the online FPS). In that game, there was no match-making like there is today. You had to join someone's created server to play a match. Well, I joined, said hello and then this kid basically called me a the "f" word and banned me on the spot. 

And with that, went my belief in voice chat lol.

This kid, now probably in his late 20s or early 30s also still remembers this as his worst online gaming experience, when this **** ********** ******* ****** ***** ** **** ***** ************ ******* ********* showed up and ruined the game by existing.

Haha!

I bet that was his reaction at the time. Like, how dare this human being come into my public server, which isn't locked at all and is open to everyone, and say hello to me! Like, what a piece of *%^*!

Naruto Ultimate Ninja Storm 2
Somebody played Deidara. You can spam really well with him. I tried everything but this charakter seemed broken at the time to the point that players could just mop the floor with you, no matter how well you played.
So that happened to me. I think the really annoying thing was that I actually came close to beating him. But his cheap tactics prevailed. And than I, lying on my sofa, was so pissed, that I kicked and broke the armrest.

I wouldn't call it awful but it was my most embarrassing moment, in Rainbow six Vegas I was playing with some guys who I had just teamed up with and they were new to that particular level, so I carefully explained that there were two enemies hidden in the next small room and if you weren't aware they would shoot you from their hiding spots so they should be careful, but having done the level with no harm I told them don't worry and proceeded to take point and opened the door took a couple of steps inside and immediately got killed the amount of laughter that generated was overwhelming and the rest of the game consisted of them warning me to be careful in case there was an  enemy in plain sight with his back to me.

Rocket League, every time someone gives any kind of feedback in the chat or disconnects after just one goal. I don't understand the need to be a dick when playing casual and you didn't get the best teammates, or the need to disconnect and look for a new game because 'you were losing' when the opponent scores even one goal. It's not really a single moment but pretty much every single session. Rocket League is a great game, but it's also a toxic one. I haven't played in a while and apparently there might be a fix to the disconnect issue (although it does sound way too strict), but I doubt anything has been done to the toxicity issue.

I'm not sure if this is special for a multiplayer game because I suppose it sounds like it might be pretty common, but I don't play a lot of multiplayer games so I don't really know. It does kind of suck though.

I've had gameplay sessions of Overwatch or Smash Bros. where I'd continue to play to get "that final win" before I logged off when I was waaaaay past the point of being tilted. It makes for such shitty games where every single error had me raging and that makes you lose and lose and lose. Then even when I did eventually get that win I'd log off in such a bad mood still.

I was working out while playing online MP. Was breathing heavy and people thought I was up to some dirty deeds. People freaked out but I was quick to let them know I was working out. LMAO!

We believe you.

Hmm I did get DDOS a couple times a VERY long time ago. Once noticeably against a guy in a cod zombies match who was making it very clear for me to be an hero and another random user took my side and he took that personally. Obviously trash talk is whatever in COD especially in MW2 and BO1 days, but that guy really gave me Zodiac vibes. 

Obviously there is the annoying moments of host migration in COD games when you are just about to get a Nuke, ect. Getting betrayed right at the last second of Halo with a perfection. Many such cases.

Then there was Titanfall 1 dying. It became literally unplayable where one supposed hacker was able to shut down the ability to find a match (did they ever fix that?). I almost have to wonder if it was a Respawn conspiracy because Titanfall 1 didn't have any microtransactions and they were maybe losing money paying for the Microsoft cloud servers. Not even really joking. It's a bit sus that their games always have problems after they make a new one and they don't fix it. Similar thing happened when they were in charge of COD where the last COD would get hacked to death when the new one came out.

Below I brag a lot so I put in spoilers to be less annoying, people might not believe let alone care:

Then there are the xbox friends who I lost track of. Some of my friends just stopped gaming because of age and such or they took breaks, made new accounts, or I took breaks and forgot to keep up with them. I had a couple xbox friends who I also had added to facebook and skype, but I deleted my facebook after college.

Outside of multiplayer I've had a few technical issues with gaming in general. Although off topic these are additional worst gaming moments:

I had my original xbox 360 break and my Wii break. I had dropped my pokemon blue after collecting all 151 and resetting. Obviously I did not know about the battery inside games back then so I lost all my save data for other gen1/2 games as well over the years. It appears that with N64 only one of my games lost its save data (Mario Kart), but I know that's coming soon so I plan on just replacing them ASAP. 

Recently I tried installing Sims 1 Complete Collection on iMac bootcamp Windows 10 and I think I screwed up. instead of trying to find solution online, I tried uninstalling and reinstalling. Problem is sims 1 has some weird glitch where its basically fused to system32 lol. This now makes fully uninstalling it impossible therefore reinstalling impossible.