Personally I would book a table at Vertigo at the top of Banyan Tree.

It's about the experience more than the food (it's London prices, and specialises in steaks - I had steaks from cows rubbed with sake everynight - but they had Thai foods as well!).

It's rooftop, open air with stunning views over Bangkok. When I was there I could see clouds below the restuarant and lightning striking the city, unbelievable. Get a sunset reservation (6pm). It's one of my most memorable eating experiences ever.

But not what i'd call a uniquely Thai experience!

Can't think of anywhere better

I think you've sold it to me.....it looks awesome, thanks and I better get booking!

For anyone else interested here is the website.
We haven't been there but did go to Sirocco( The Dome)- only for a couple of drinks though.
Have a look

You're all very very VERY brave to go up there. They both looks fabulous but wish they were all on the ground.

Cheers Geri