I joined "The Zerg" a few weeks back. Very active economy. It is a PVP server but with dungeon finder and what not you can skip most of that. The guild is casual but we group up from time to time for For The Horde, BGs, BH, TB, etc... the guild is almost max size with over 800 members (boxed remember) so two sister guilds were formed The Terran and The Protoss and with a mod/addon you can chat with all three guilds. Seems to be a good group of people, vent server and people in it. At any given time I typically see 2-3 boxers on plus 1-5 solo boxed "friend"/"family" toons.

If interested give a yell by doing a /who protoss, zerg, or terran and ask for oathbreaker or tiny.