Creon, Jocasta's brother, comes off as a pretty nice dude in this story. When the Sphinx is causing problems, he doesn't mind abdicating the throne if it helps save Thebes. Later on, he assists Oedipus in every way possible to help find Laius's killer and stop the plague. For a lot of the time, he's the levelheaded voice of reason.
Click here for more on this side of Creon (as seen in Sophocles' Oedipus the King). Later on in his career, Creon becomes a more controversial figure. You'll find more on that in Sophocles' Antigone. Click here for that and here for more on Creon in general. What can we say? We just can't get enough.