Concierge.com's insider take:

Another of Bangkok's riverside bastions of luxury, this Peninsula stares down its rivals—the Shangri-La and the Oriental—across the Chao Phraya from the Thonburi side. Of course, that's the Peninsula's one drawback: everything worth seeing in Bangkok lies on the other side of the river. The hotel makes up for this failing by outstripping the Oriental in sheer style (that, and ferrying guests across the river all day from 6 a.m. until midnight, a lovely way to commute). It's also not far from the Skytrain. It was designed so that all 370 rooms and suites get the coveted water view, especially valuable at night when the city skyline is lit up. The spacious rooms have a distinctly Asian flair, right down to the contemporary art. Even the least expensive rooms have teak foyers, silk-covered walls, and marble bathrooms kitted out with mod fixtures and TVs. The 2006 addition of a spa gives guests the option of Thai, European and Ayurvedic-inspired treatments. Among the five restaurants, Jesters is tops for food—haute Pacific Rim (think wild Australian crocodile served up ceviche-style)—but its modern style can't hold a candle to the ambience of Thiptara, where guests enjoy traditional, home-style Thai dishes like grilled prawns dipped in tamarind sauce under salas (traditional, open-air, pagodalike teak structures) with live khim music in the background.