I like the idea that one of the races the driver would have to win would be his home race. Obviously this doesn’t work as well for a national championship like Indycar but for F1 drivers to win at home is surely the best feeling you can ever hope to achieve. I know this is flawed as not all driver nationalities are represented on the calendar but perhaps an additional caveat to the idea of a triple crown, three races and then your home race on top would be a grand slam as someone mentioned above. So for me Monza and Monaco have to be in there, then either Spa or Suzuka (probably Spa) and then your home race, whatever circuit that may be.
I know winning at Silverstone would mean more to me being English with the home support than it would at Monaco or Spa, even with the history and challenge of driving there. But then perhaps that’s because Silverstone is one of the real classic tracks of F1, I suspect I might feel differently if I were Spanish and my home Grand Prix was Valencia or Barcelona!