"Champions Online" is developed by Cryptic Studios, the guys behind "City of Heroes." It's hard not to see this game as a direct sequel, as it's a super hero MMO with improved graphics and a broader feature-set. But, obviously, the game has the "Champions" IP to work with, allowing the developers to use the characters and environments introduced in the pen and paper RPG.
To further differentiate itself, Cryptic seems to have put a lot of thought into innovating the single player experience in "Champions Online." One thing in particular that sticks out at me are nemesis missions. Here's the set-up:
You're playing through the game as your created hero, stopping crime, doing good, etc. But as you progress you keep hearing rumors that someone's been tailing you. You don't learn too much about them until the police show up and inform you that you've got yourself a nemesis. Then they ask what he or she looks like.
It's here that you re-enter the game's robust character creation system to create your own nemesis from scratch. From the costume to the powers. Hell, you even pick his or her backstory and what sorta minions they have.
Once you've gone through all this you can take on "Nemesis Missions." These missions will directly involve your nemesis, forcing you to go up against them in a variety of ways. You'll see your created villain attacking you, wreaking havoc on the city, spouting evil non-sense. And so will your friends. You can bring folks along with you as you complete Nemesis Missions, so they'll see your creation as well.
Eventually you'll be able to lock your nemesis away in the "Champions" prison, at which point you'll start from scratch with another foe. But your original nemesis is not forgotten. There's a chance he or she will break out, along with any other past nemeses you've jailed, resulting in a "Rogues Gallery" of bad guys created just to make your life a living suckfest. And so the cosmic ballet continues.
I know MMOs are not everyone's cup of tea, but it's innovation like this that makes the genre unlike any other in gaming.