I've been to vertigo. Nice place for a classy dinner. I love Banyan tree hotel. Had the most momorable stay there 2 years ago.
You could try Baiyoke sky for the night view too. I've been to another high up restaurant, i think it's called Sirocco. (from my hazy memory)
http://www.2bangkok.com/2bangkok/bui...te/state.shtml