There are an enormous number of hotels in Midtown, but if someone else is paying or you are splurging on a nice place then
The Peninsula Hotel is as nice as any. It's located steps away from 5th Avenue and has a great luxury breakfast place on the 2nd floor that's expensive, but perfect for a business meeting. There's also a great bar on the rooftop. They did an excellent job on the Christmas decorations this year.
