I was kind of a loner around that level. Solo L. Guk in the safehall. Just use Pacify and, if you pull a wizard, use DA right after you pull because it will chain cast 4 to 5 times before it comes to hit on you. Make sure and have Magic and Fire resist on yourself. You will often find a Pally or mage down there to group up with also.
Katta Graveyard would be easy also. Just Invis to undead, run around GY till one pops, then pull it out to the walkway. If you get two pops, just stay invis to undead till they de-pop.
You should be able to take out the Spectres in Oasis soon also..Maybe around 44.
All depends on your gear though:)
Best Group Exp, would be City of mist, Lower guk , Hard LDoNs, and the Spectres in Oasis.
Use the LFG tool and put a group together for CoM. Use the Field of Bone portal in Pok and run to Emerald Jungle. It's really not hard to get to anymore.
I didn't care for Dulak Harbor exp much, it is steady if you have a group though, and you get lots of Zombie skins to sell.
That's all I can think of at the moment..