Raising a very difficult, rebelious, angry step-son to adulthood -- including graduating from high school (not in special ed. despite the fact that his biological mother thought he needed special ed.) and obtaining a respectable job in the milatary. Now he is planning his future career and standing on his own!
I was most proud when the twin step-son toasted me at their high school graduation for being the "best mom a kid could ask for." (And biological mom was in the room.)