As someone that has played MMOs since the hayday of Ultima Online (yes, I played and was 12 when I started), there was always a certain difficulty that many of us yearned to find and triumph over in these games. UO had the difficulty of being an open-world, sandbox PvP game where the word "raiding" meant going and killing a group of players, or a guild, that was currently in the process of completing a champion spawn (think open-world, raidable dungeon). To be successful not only meant getting ALL the lewts, but also bragging rights on the forums. And yes, bragging rights were important in that game [/rolleyes].
When my friends finally talked me into trying World of Warcraft (right before the release of Burning Crusade), I was quick to learn that raiding had a completely different meaning. Not only were the dungeons and raids not open-world, but a group of players could not raid another group as they were progressing. I did find this quite disappointing, but perhaps I had been spoiled by UO.
In the beginning, didn't pay any mind to the PvE side of the game and mainly stuck to starting fights in Stranglethorn Vale, doing back to back battlegrounds, and dinking around in arena on my hunter. It wasn't until after the release of WoW's expansion, Wrath of the Lich King, that I finally started to partake in PvE and I eventually stopped nearly all the PvP I had formally enjoyed. Of course, by that time, I was slightly enraged over the hunter nerfs (in PvP) and had decided level up a Death Knight and Shadow Priest.
Most of my friends had quit or left me for other servers, so I was forced to PUG my way through heroics and raids. I couldn't be hassled finding a raiding guild, especially one with strict guidelines. Naturally, the group finder in WoW made it easier to find a group to run heroics with and within a few weeks I had both toons geared enough to start raiding the normal mode of ICC (Icecrown Citadel).
As a DK it was hard to find a group simply because finding DKs to fill a raid up was like finding hay in a haystack. They were very common and, often times, would be the first class a raid group would no longer need. Not to mention half the PUG groups LFM DPS usually had unrealistically high expectations on the required gearscore for a simple normal mode run. In my experience, high gearscore usually didn't make up for an unskilled player with no raid awareness.
After a month of unsuccessful attempts to down ICC on my DK, I switched full-time to my Priest and respec'd to Disc(ipline) so I could get in as a healer. This meant going through heroics again to attain different gear, but I was ready after only a week or so of grinding. Each raid only took one or two heal spec'd priests (depending on the size of the raid), but I could usually find a spot within minutes of searching in chat. A lot of times groups would even make an exception for my lower gearscore just to fill the spot of heals/priest.
It definitely goes without saying that running in PUG groups for raiding was probably one of the most frustrating and difficult times of my gaming career. Naturally the people on my server weren't the best PvErs, but then again the server I was on at the time had primarily PvPers and was rather unpopulated. I thought maybe transferring to a higher populated server would help and I was only half right. Generally speaking, half the PUG groups I got into were people gearing and running ALTs, while the other half were just as unskilled and frustrating as the previous server.
There were many times I even attempted at leading raids myself and I did a decent job for someone who had no previous experience in doing so, but even then I still ran into the usual problems I'd had in other groups. Some people lied about knowing the boss fights, some people got angry and would leave the raid if they didn't win a loot roll, tanks would blame the healers for a wipe, hunters would accidentally pull the boss before everyone was ready, and this list could probably go on forever...
At times, running a raid was sometimes as hard as trying to keep a group of kindergarteners under control. The Professor Putricide fight was, by far, the biggest nightmare in all of ICC (at least for me). Between people not paying attention to the different colored slimes that spawned, not even knowing what the different slime colors meant, getting hit by all his abilities he would throw at people, or it not being obvious to some that standing in the green ooze was a bad thing, this was a fight to tell if someone was good at their class, good at raid awareness, or just an overall noob trying to get carried.
There was one week, however, after about a month of raiding on the new server, that I got lucky and found a group, most of which had previous experience downing ICC on their alts and, after about six hours of raiding, we managed to down the Lich King. It was easily the most rewarding and accomplished feeling I had felt in a long time in a video game. Not only had I finally downed the Lich King, but I had done it entirely through PUG-ing. I had a lot of bad luck in my PUG career, but I still had a lot of drive to defeat him, despite all of it.
Since then I've raided in RIFT and SWTOR, but instead of PUG-ing I have a solid guild. I do have a lot of fun running with my guildmates, but there is just this level of difficulty missing when running with an organized group of players that are used to playing with one another, rather than running with players that don't know their heal abilities from their DPS ones. Though frustrating, I will admit I definitely enjoyed, and even had a lot of laughs, when running in PUGs.