Going to Singapore in November; my travel agent has a limited selection of hotel properties (Royal; Royal@Queens; Peninsula Excelsior; Swissotel; Marina Mandarin; Ritz Carlton; Regent; Marriott, and River View). Excepting the River View, which may be, I think, too far away, the three in the title are the most expensive (so, I assume, are the better hotels). Any thoughts on which would be best?

Also, what are the facts about the Sia Hop-On Bus for sightseeing? Thanks!