If you've got a favorite spot to hunt, reply here and help others.
I play as a trio, and my recommendations will be as such. I always recommend making a full group if you can as things are just easier.
1-12 noobie areas doing the noobie armor quests.
12-24 Upper Guk - Changed to be all undead on this server, so almost no runners outside of spiders and crocks. Especially great if you have any classes that nuke or slow undead.
24-40 Lower Guk. At the lower levels kill the mobs by the entrance, Break the 3 spawn in the bedroom. If you have a class that can pacify/lull can pull the barbed skellies and others. As you level up, camp the assassin to get a pre-nerf dark elf mask.
40-51 A few different spots. I do Lower Guk mostly, but Sol B also works. Another spot if you want the ability to afk if needed. High Hold Keep, killing guards and/or Nobles/bards.
51 Veksar I hear is good. I struggled in Corathus Creep with another boxer, so we had 6.
55+ Corathus Creep.
AA Farming at 60. Corathus Creep, Taka, really lots of zones as you'll need to farm things for epic quests.
There are lots of paths to take. Sometimes I take a different one while leveling up just to experience old content. Runnyeye is a fun zone if you haven't done it before near Misty Thicket. It has runners though, bring a snarer.