I never really had chores as a kid either. I was responsible for keeping my room somewhat tidy, for putting my dirty laundry in the hamper, and really for helping out with anything I was asked to do. Not having assigned chores didn't seem to hurt me.
DS, 11, has to keep the clothes off his floor, put his dirty clothes in the hamper, keep his video games tidy, and help out when needed. He's a fairly eager helper, so we haven't done official chores with him. His main chore is to do well in school, and be a helper at home.
Nan