During the day it's hit and miss in the dungeons. In the evenings it seems that most large groups are on guild hunts. Painted caves (where you found the trogdolytes) is a good spot. The spawn is fast and there always seems to be someone in there. The dungeons arent too busy as they were in years past as there are so many places to hunt nowadays. If you go to Ilshenar gate and choose spirituality, you can go into the twisted wield area. I wouldn't recommend it on a necro as the negative karma will attract all the pixies in there, but warriors have fun in there.
You will need to get the quest first before you can enter. To get the quest go to heartwood (which is in yew) and go to the person named colendar, and accept the dreadhorn quest.
The mondains legacy dungeons are attracting most players these days, but the creatures are far more advanced than say, deciet or shame dungeons. Some of the monsters, without proper suits and knowledge can kill in one hit!