Well, all CLAMP really did for this series was the character designs...but I think they did a great job, myself. One thing worth noting is that the director has said he doesn't care much for fanservice characters, so you don't have to worry about any unrealistically-busted girls running around. Sure, one or two are well-endowed, but that happens in real life after all.
Of course, the real agony is the fact that the final two episodes of this season won't be coming out until Summer...
gonk The only consolation is that it means the wait for Season 2 won't be as agonizing...
And it may seem like a cop-out, but I think my personal favorite characters in the series are Lelouch, the main character, and C.C., the female lead. They're just so much fun...Lelouch is smart, cool, and badass (like Light Yagami, if he had actual human feelings like love and remorse) while C.C. is the right mix of mystery girl, brat, and romantic lead. Piccies for those interested...

That's his "Bring it on" face.

Believe it or not, she's mourning the "death" of a giant pizza.