This post was from a user who has deleted their account.
For me, it was soloing Stratholme 30+ times, as a 70 holy pally, for Deathcharger's Reins, and on the very last try, the "I am so tired of trying for this" run, it dropped. =) May I never go in there again. ;)
I have to say, my best epic drop was these pair of leather gloves, (http://www.wowhead.com/?item=867#dropped-by) at level 40. When I first saw them, I about died, I just started the game a couple of weeks before, and it was my first chance to make real money. I got it in feralas, when I was trying out drain tanking, and it actually working... I ended up selling it on the AH for 100g, and that money lasted me for a month or so... In retrospect, that's pocket change now, but still, at lv 40, it was amazing.
Most epic drop for me had to be the T4 Druid tanking chest. I had already got my T5 pants but couldn't wear them cause it would break the 4 set for me and T4 druids get 1400 armor for tanking for the T4 4 piece set. It also has 3 gems slots to boot. What a great help it was we had already been doing SSC for some time and this upped my HP about 510 by allowing me to use 4 gems slots, total 3 from it and 1 from T5 pants and yet keep the 1400 armor. Sadly I wore that set into WotLK because our guild broke up and split 3 different times never making it past 1st 2 bosses in BT.
My most epic loot probably isn't as believable as many people will take it. But it was right after the release of the Sunwell patch, and everyone was on the Isle of Quel'danas doing dailies and trying their skill at Magister's Terrace. I wanted to try out Magister's Terrace on normal so I could unlock the heroic, so I got a guild run together. Everything went smooth until we got to Kael'thas, which seemed like a rather difficult fight, although I understood the basics of what to do. We gave him a few tries and we kept wiping but I always seemed to survive. So we give him one final shot, and we get all the way to the anti-gravity phase. At that point everyone is working him down and then they are taking too much damage to recover. So I, being the capable holy paladin, decided to try and solo him from 50% health. I swam through the air like Micheal Phelps and healed myself of any damage I took, and when I got back on the ground I would slowly whittle Kael's health down to zero. I popped mana pots as much as possible and just kept myself healed so that I was ready for the next anti-gravity phase. I threw one final Hammer of Wrath at him and he became probably the most epic battle I've ever done.The best part was when the hatchling dropped and I lost the roll to the mage in the group. Ahhhh, irony.
The most epic moment I have had in WoW was when I got my Ateish. Just to have an entire guild of people working towards one piece of loot was so awesome!
I think my most "Epic" drop ever was my Azure whelp.I had farmed two days to get crimson whelp and then i decided to give up...I went to orgrimmar and had nothing to do so i decided to go check those mobs who drop Azure whelps...when i finally got there i started killing them and got Azure whelp right away from third mob i killed :P My friend went nuts when he saw my new whelp :D