which Triple Crown race is the best to be?

The Derby, of course. The Belmont can be bigger, only if you have a Triple Crown threat. And it's usually the graveyard of the TC hopes. Funny Cide, Charismatic, Smarty Jones, Real Quiet, Spectacular Bid, California Chrome and many more. It's a mile and a hald, it's three weeks after the Preakness, instead of two and three Grade One races in six weeks is tiring.