Built in 2006 and immaculate, with an impressive contemporary art collection

Central location on border of SoMa, Union Square, and Financial District

Close to museums

Large bathrooms with a separate tub and shower

Large, 42-inch TVs with HD channels

Acclaimed New American restaurant and grappa bar

Elegant rooms with luxe amenities

Excellent service, plus 24-hour room service

Open-air gym with modern equipment

Hi-tech rooms with 37-inch flat-screens

Beautiful bathrooms with deep tubs

Iconic hotel with lots of history; built 1907

Spacious, well-appointed rooms -- iPod docks, bathrobes, Frette linens

Stately, historical building; elegant decor

Premier luxury spa

All rooms and common areas renovated in 2012

Large, chic rooms all have stunning high-rise views

Big bathrooms, most with deep soaking tubs and walk-in showers

Large, well-outfitted rooms among city's best

Soundproof windows, quiet rooms

Twice daily housekeeping; nightly turndown

Up-to-date units with top-end appliances

Unique setting in Ghirardelli Square

24-hour butlers

Great spa with an outdoor "Bathing Ritual"

Ideal waterfront location; great views and restaurant-lined block

Free in-room Wi-Fi and large work desks

Second-oldest hotel in city (opened 1904); fascinating -- and sordid -- history

Rooms in the tower are spacious and modern.

Borders Union Square, great for people-watching and luxury apparel buying