I think one of the best ones was opening one of the oracle eggs on christmas day and getting my green proto-drake. I still call it my christmas present from wow.
When I got my Glory of Icc Raider and my drake.
When I got lil Xt from the pet store and he brought back all of those memories from hardmode Xt back in wowlk days, Just running around SW screaming "i'm ready to play" and destroying everyone's toys
Finally, after all my time farming, getting the "Mountain o' Mounts" achieve.
Fishing up my turtle mount
Onyxian drake last week was a HUGE monkey off my back...did it every week since it returned in 2009 and solo since MoP dropped,
I would halve to say that my two favorite accomplishments are, Swift Razzashi Raptor and Hero of Shattrath were sweetness. Among my many other feats, it is hard to choose. Sulfuras, Hand of Ragnaros and Thunderfury, Blessed Blade of the Windseeker were sweetness when I got them too. And here is the proof that I have them, http://us.battle.net/wow/en/character/terokkar/Mailorious/achievement#81
My first, and only -for now- lvl 90 char :D
Mini Tyrael would be cool
One of my best achievements, would have to 10man Tribute to Insanity. Which was made even harder, when we decided to heal it with two priests, when a paladin was practically mandatory.
To get to LVL 90 and get 1 of every Battel Pet :o)))
"What a long strange trip it's been" That felt so freakin good. I remember finishing it in AV.
God how i want a magic rooster they are so cool!
My Time-Lost Protodrake! Took me a lot of camping but worth it!
Hoping for Invincible's Reins to drop and winning it! I rolled a 91 on Smoldering Egg of Millagazor last time, so hopefully my luck gets me Invincible's Reins.
I am looking forward to one day obtaining all the transmog gear I need for my Warlock to make him look perfect.
Tyrael's Hilt! I'm coming!
Getting My Flameward Hippogryph. Took me a couple Months but now its one of my favorite mounts well worth the grind.
Was actually just talking to a guildie about this.post raid Bear mount runs (10man) and 10man heroic meta achievement for the Frost drake.10 players, that stuck it out, learned to move as one and finished. (10th bear mount just hours before it was removed.)
I would love to get one. Big fan!