Suggestions for free to play MMORPG please!

I was a long time WoW player, quit 2 years back. Now I’m looking for a free to play MMORPG that I can play casually and still enjoy it. I’d like something similar to WoW: nice character models and items (no cartoonish stuff), good community with contents that require/encourage a lot more players interaction/coordination (I played some Diablo 3 and hated it due to the lack of this), and to the very least, a decently to well established pvp system.

Any suggestions will be greatly appreciated! Thanks in advance!