Lots of interesting information here.
I'm always struggling with finding balance between family life and letting the kids explore their interests. Whenever possible it has been more convenient for the family if several of the kids could do an activity together, say all do town rec baseball rather than one in baseball, one in soccer, etc. Given the span of my kids ages (5 kids ages 8 to 23), that hasn't always worked out. They are all individuals, and we've tried to let them try things they think they might like, and let them drop/change if it isn't what they want.
There has been mention of music, but I haven't seen anything about drama. Our school district loves its music program, and that tends to bleed over into the HS musical and drama club. The question in 3rd grade is not "Do you want to take an instrument?", it is "Which instrument do you want to try first?", since many kids eventually join more than one ensemble, and learn more than one instrument within an ensemble. My older son did viola, bass, electric bass, tuba, and trombone. It is not unusual for kids to graduate w/ double or triple music honors.
I work in a library, and have run a teen/youth drama club with some homeschool members; the kids do a summer play, and we've also done something we call Classic Horror for Halloween. The summer play uses a commercial play, but Classic Horror gets the kids involved in more than just acting. They become producers, directors, write/adapt the scripts (from classic works of Lit, hence the name), set designers/builders, promotion, etc. The group is divided up into 4-5 smaller groups that work independently, each putting on a 10 or so minute skit/scene from their "work". We've covered the expected: Frankenstein, Jekyll & Hyde, Dracula (an all female cast). We've done Shakespeare: Macbeth's weird sisters, and Hamlet's scene w/ the ghost. We've also done fairy tales (Hansel & Gretel) and musical numbers (Sweeney Todd). At the end of the night, after 20 or so repetitions, we all run thru our acts one more time for each other, and the kids are always so fabulous, cheering and applauding each group's amazing results. I've always been less than thrilled w/ the winner/loser aspect of sports competition, and the different scene groups was a nice counterpoint to the sports paradigm. Everyone could work hard and do their best, and yet still enjoy and be amazed at what the others achieved.