So an interesting idea I had the other night:
If we want to make the platinum leaderboard into more of a game, we could do something like give bonus points to people that have the only platinum for a certain game (like I have the only platinum for GH5, and someone has the only platinum for GT5, etc). That would give other people, especially those who want to compete in the rankings, more incentive to get a plat in those games to eliminate the other people's 'bonus.'
Just a thought. Might make things fun and put a nice twist on things.