Since the merge there have been more people and more guilds. I would like to share some of the biggest and most active guilds that are from Gerrant and Yall ought to join.
-Risen
-ProjectX
-United
-Invaders
-Hollows
-Dragon
All those guilds are high level and have high active members as well as level 40. Choose one of em to join, you wont regret it.