Have been in BKK for 2.5 weeks and have had some very good eating experiences, will do some kind of report in due course.
Wanted to put in a strong word for Le Lys (http://www.lelys.info/) where I had lunch today upon the recommendation of a local friend.
Lovely setting (quietish side street, old house, garden, terrace, petanque "court" in the back), charming people (owners are a French/Thai couple hence the petanque and I was served by the wife's sister) and the food was great (lemongrass salad using the inner layers of the lemongrass served with fried peanuts + shallots + dressing; tom kha gai, what a difference galangal makes with its mellow rhizome flavour; sticky rice + mango). Washed down with a pineapple "shake" and an espresso. Cost = 480 baht.
On my way out I came across their DVD collection and was allowed to borrow three titles gratis on a trust basis which I liked a lot.