Soccer and basketball
My daughter, Ashley, is playing basketball for the first time. She's 10. She's played soccer several seasons. In the bleachers, soccer is to basketball what relaxing and enjoying the mountains is to driving through NYC in rush hour. Basketball is a bit more loud and intense, and parents are making the most noise.
I'm with Cal Ripken: let the kids play, watch, and encourage them when they do well. And if one has an impulse to tell the kids what to do from the stands, then sign up to coach.