One of my favorite hotel to stay in not only in SEA but actually, possibly in the world, is The Metropolitan. There is something really zen-like about the hotel. You don't feel that it's a business hotel and constantly buzzing with activity. There's an immediate sense of calmness the moment you step into the entrance and everything about it is fantastic. Also, it's owned by Singaporean Christina Ong so yay to supporting our local businesses.
The rooms are supposedly one of the biggest within Bangkok. I love how spacious each room is yet it is not overwhelmingly large and I feel comfortable and cozy. The furnishings is all simple wood with clean lines and minimal fuss. Service is impeccable and the best part is the Glow breakfast which is mostly organic and healthy food, which I happily filled up my tummy with daily. Quite a good detox (of sorts) I must say :)