I've had the most troubles with groups in Sunken Temple, so many attempts that people rage quit on. Then i got into a group yesterday that was mostly all new. Frankly the best group i've had so far, and restored my faith in the game and community. The tank seemed to have a hard time holding hate, took a crap ton of damage, and died several times. Battles took a good time longer than they probably should. No one raged, and it was the first completion in several attempts with groups who said they knew what they were doing. The tank even got two new pieces of gear, that he used right away.

Second one i look up to is a titan where none of us had done it, and no one quit after many, many wipes learning what to do.