My take:
1. Columbia
2. sinai
3. Cornell
Columbia is the absolute best program in the city!!! Great rep, great hospital, world renown.
Sinai is a hidden gem, a diamond in the rough. Great clinical exposure and nice mix of underserved/ upper east side.
Cornell is a decent place but very stuffy, very hardcore, very unfriendly. And don't believe their hype: the service patients (aka poor people) are few and far between. clinical skills are compromised by upper east side patient population's unwillingess to let you "learn" on them. You don't run into this problem at Sinai or Columbia.