2 days ago I was invited in the Rang Mahal, the indian restaurant on the 26st Floor from the Rembrandt Hotel, Sukumvit Soi 18.
The best Indian I ever had ! I think it is expensive as a Singha beer was 200 thb for a bottle, but I did not have to pay the bill, luckily . You have to make reservations to have a table with a view :022617100.