I keep thinking about going back to Champions Online. Unfortunately though, ever Superhero MMO is going to find itself measured against City of Heroes/City of Villains for me, and thus far they all rather fall short. Might not be fair of me, but it's hard not to bring many years of enjoyment and a vibrant RP Server community to bear on whatever I try.
Keep meaning to look into Secret World as well. I was really excited about it when it first came out, but the reviews of it tended to be rather bland, so I never really dipped my toes in.
And Tsenta, thanks for the feedback! I have no idea how or where favor is generated, but I'll look into saving it up for the Artificer while I tool around with my Warforged Rogue/Wizard. And my Human Monk. And my Human Rogue/Pally/Fighter. And... well, you get the picture. I am an altoholic.