My proudest moment was getting the hard mode achievements in heroic dungeons with a 5 class team. I remember that boss in Drak Tharon Keep , where you had to interrupt him before he morphs into a rhino, I forget the details, but I spent WEEKS on that one boss, and when I finally got it, I was literally jumping up and down screaming with joy... My wife was very confused at the time...

I had the most fun running 5 ele shaman during AV weekends, and protecting balinda, then back capping, which numerous times we won the "perfection" achievement. It felt good to have that kind of domination, and coordination with the others to keep all the towers up, while slowly working our way down the map.