The (Mandarin) Oriental
The grand old Oriental (Bangkok's citizens have no use for the Mandarin chain's prefix) suffers by way of comparison to itself. Past attention to every guest's personal detail has strayed a bit, and the lobby entry is starting to look like a U.S. embassy from the 1950s. The rooms, while bright and thoughtfully appointed (Bose stereos, teak and silk furnishings), are boxy; the restaurants (Thai, French, casual) could be considered either elegantly bland or blandly elegant. The linen-white Authors' Wing is a great venue for high tea, but not much more seems to happen there.
Still, the hostelry's equally effortless amounts of character and service, plus its access to the city's grubbily romantic river life, nonetheless make the Oriental the obvious choice. Compared with contenders like the Peninsula (on the other side of the river), the more classically understated Sukhothai Hotel (misplaced amid bank towers), the suited-for-shopping Four Seasons and the new faux-antique Eugenia in the Wattana district, the Oriental comes out on top by a margin as thin as the ghost of Orientalist guest W. Somerset Maugham. See www.mandarinoriental.com/bangkok for more.