Protector Vigilance
Protector TFs
To a lesser extent, Protector Watch (it is a lot more strict about behavior, but it gets chatter now and then).
My Stories
Look at that. A full-grown woman pulling off pigtails. Her crazy is off the charts.
I use "Protector TF's" for the most part. Its an open channel with a good amount of active people to help you do WSTs, other Task/Strike forces, and iTrials.
If you like redside there's also Global Villains, it's meant to be for all servers but 99% of the people in the channel are from protector.
Definitely Protector TFs and Protector Vigilance if you're looking for teaming-oriented channels...ProVig tends to have a lot more general chatter than ProTFs does, and many people will advertise any events on both channels, but they share a lot of the same members.
Being active in global channels is also a really great way to get your name out there so that those folks who tend to team only with people they know and "friends of friends" will be more likely to pick you up as a teammate. 
City of Heroes taught me that when the world is burning, you don't just stand by and watch, you grab a fire extinguisher and do whatever you can to stop it-even if it's not much at all. Sign the petition to keep City of Heroes alive HERE.
@MissKyo, Leader of the Teamsters coalition on Protector
One of my questions concerning getting a notice of the well by doing the weekly strike target gave me some useful advice that I to take full advantage of. So I need to ask the following.
What active chat channels do I need to join that would help out not only my main (level 50 dark melee/regen scrapper) but all of my characters on this server?
Ebony Fists: Level 50 DM/Regen Scrapper, Gloom Piston Robotics/Dark mastermind level 34, QueenFireMare: Level 34 Fire blaster (pure fire),