This post was from a user who has deleted their account.
My personal favorite would be Death to the Warchief. Mainly because of the memories tied with it. The horde of my server had several people who would camp our auctioneers and bankers daily. Most of the time we ignored it, but one day a rogue who was a strong member of the community came up with a brilliant plan.He called together the leaders of the top guilds of the Alliance and discussed his plan to strike back at the horde. The plan was simple, the guilds would meet up and divide among the horde cities and strike down their leaders, wreck their auctioneers, and plunder their bankers for as long as possible. Communication would be made through trade chat. Being the largest guild of the four guilds that participated, we were placed in charge of assaulting Orgrimmar. We got in vent and gathered together, joked around and then charged. We ran into the city spamming our shout macros and made way to Thrall. A resistance had already gathered, perhaps someone tipped the Horde off. We clashed, and the horde could not hold us back. Soon Thrall and Vol'jin lay dead on the ground, however not too quick to celebrate we headed toward to the Valley of Strength. For two hours, we cut off all of their access to their bankers and auctioneers, striking them down as they spawned. We killed anyone who stood in our path, and made haste to protect those who strayed too far from the group. Soon the guilds who had finished with the other cities as well as our fellow pug groups met up with us in Ogrimmar as well. It was such a blast, perhaps the moment in WoW where I've had the most fun. To remember the moment forever, we gathered together on top of the Ogrimmar bank and poised for several screen shots which would later find themselves on the realm forums. Such a great day to never forget.
My favorite would have to be Avast Ye, Admiral!.It was fun, getting people to help me kill green people.I met the love of my life, killing green people.I made friends that I have met in person, all over the world, killing green people.The green people still hate me, and having to avoid their towns can be tedious to say the least, but I love getting whispers from people, asking why my name is "Bloodsail Admiral Virust"(And killing green people)
Definitely my pre-Cata Loremaster achievement. It took so much mindless grinding. :P
, seriously, a whole year to get an extra 30% in flying BEFORE you could buy it.... loved it.
Gotta say it would have to be between 10 man Obsidian Sanctum and the Rhok Quest, we spent a few thousand gold and a ton of time struggling with it, we finally did it with 4 people left alive at about 5 in the morning, but Rhok I did from home on a dialup connection, through sheer skill, and by that i mean blind luck, because i still don't know how i killed that Silithus demon on a dialup connection
I'm a casual player, so getting "The Argent Champion" was a big deal for me. Simple enough to get, but quite a time sink when you don't have much time to play. :)
My favorite achievement was Veteran of the Wrathgate Veteran of the Wrathgate. The quests that went with it were unique and told an amazing story. I love to see epic story lines! *edited to include achieve name, not sure how to make the links work*
My favorite achievement has been Grand Marshal. I reached it back in the day as a level 60 resto druid. My druid Zôryal is the only druid on my server to have reached this level. I am very proud of that fact .After that, of course, I felt the need to get the Insane title.
Realm First! Death's Demise I haven't used any other title ever since I got it during wrath. Best title ever!