I think my favorite hotel here is the Mandarin Oriental - it's gorgeous. Also, the Waldorf & the St. Regis are nice.. try to hit the St. Regis for dinner if anything - so yummy!
As for clubs, well it really depends on what your style is.. there's a lot of clubs/bars. I don't really club too much.. I prefer bars/lounges, but when you get here just look around & you'll find the place that fits your tastes. My favorite bar is the King Cole Bar @ the St. Regis but Buddha Bar, Bar41, & The Pegu Club are good places too!