42 to higher
On my recruit a friend team, I'm now at level 42 with the mage and priest. Grinding in the dungeon Maraudon. I honestly didn't like this place much the first time but now I'm getting used to the map. The dungeon is very complex and hard time get through if it's your first time. This is not like Scarlet Monastery where the path to the boss is very short and clear.
So far at level 42, I'm still too low for all but one quest in Maraudon. Hopefully this weekend I will hit 50 and get near the limit for a 70 to solo an instance.
After this I'm not sure what else I want to do. I do have a 20 rogue that I would like to level higher but might make a warrior to team up for fun. If I do, I'm going to not do any questing and just push them up to the mid 50's as fast as possible.