Current in-game factions are, in proper tiers:
PvP Gods: Ultra Violence, Muhosransk, Social Warriors
Noob Lovers: Peacekeepers, Knights of Blood Oath
School Yard Bullies: The Khans
If you are a shithead, The Khans may be the faction for you. No greater collection of autists and bluesuit killery will you find... Too bad that gets old fast when you realize TKs khan't hold an erection a minute and can hold towns even shorter. TKs *used* to be considered a TB threat based on their sheer swarm numbers and persistence. Individually, their skill is pretty shit. Their most active members at the moment are Dende (dungde) and your mom.
When it comes to camaraderie and building skills
OGG The Knights of Blood Oath reign supreme. OGG were semi-famous for their many TC attempts (which got crashed my Muhos, SW, and Khans at the same time) and their habit of shoving an M60 in a noob's hand at gunpoint. After the disappearance of The Pain Gang,
OGG The Knights have taken to more peaceful methods of recruitment. See any Knight in hub to join.
The Peacekeepers have historically focused on crafting, but are looking to expand into PvP. They have
a forum of their own where you'll need to apply if you'd like to join them. The PSquad is, without a doubt, some of the kindest people I've met.
The PvP Gods require at least age 16, a microphone, and at least level 24 (SWs and Muhosransk require 40) to join. This is where the game gets serious on a team level; all of these players have considerable individual skill and work well together. 7 v 7 fights are not uncommon.