That mission with the trebuchets, I recently went back to do for fun and I killed all the groups of chars by myself without using the trebuchets. It was really hard tho.

As for my favorite hunting spot, its deffintly The Underworld, if you dont know what that is, its a dungeon that you can only goto if your country has the favor of the gods. Once you have favor your group has to pay 1000 gold to the shrine of belthazar and you get teleported to Underworld where every monster is level 26 or higher. The loot and gold you make there if you survive is amazing and theres quest there that give out 5000 to 10000 xp.

You must be level 20 and Ascended to enter this dungeon though.