Not sure if this is the first Pickup Group to defeat the Evil Anub’arak on the Trial of the Grand Crusader (25, heroic), but I think it is definitely worth mentioning.
I think it is pretty amazing to gather 25 players and reach Anub’arak with 49 tries left in the first place, there was a wipe on twins, and then to need only 7 further tries to kill the final boss of the Trial of the Grand Crusader.
The setup was far from perfect, for example we had 1 ret paladin in like 50% tanking gear (due to lack of alternatives), and there were also many alts which makes this kil even more impressive. A big /salute to Treebearman from Pacifism to get this started!