New York at $12,595 a night
Thanks to Trendscape, according to this Reuters story:
Forget puttin' on the Ritz. Try puttin' on the Mandarin Oriental.
New York's new Mandarin Oriental 250-room hotel offers a suite with a $12,595 nightly pricetag, beating out the Ritz-Carlton by almost $100 as the costliest overnight lodging in the Big Apple.