SK is by far the best on the trek from SIN-BKK. Fare is about S$275 + taxes rtn (around S$41) and then departure 500 THB out of BKK if on a return trip.

I prefer SK as it's an A340, ask for row 31 h if possible, lots of leg room (exit row). If you arrive early in SIN, they often oblige (say 4 hours, early checkin).

The food is always superb and delcious, service is excellent for a european airline, aircraft new, and you'll enjoy the camera which films the landing and taking off you can view. The inflight entertainment system is superb with touch screen and lots of things to fiddle with, before you know it you'll be in BKK. You can enjoy the TG *G lounge while you're there if going back to SIN, they have a section cordoned off just for SK travellers, 15 min free net access.

There are cheaper flights to BKK, around S$200 (turkish, swiss, etc - http://www.reliance.com.sg) but i'd opt for this one. Business isn't too much more, and is worth considering too. If a star gold, perhaps ask the staff at the gate for a comp to Economy Extra, they'll often oblige. You are unlikely of a comp to biz as they generally reserve these for EB Golds.

If you want to see what the meals are like, have a look at some of my pictures on http://www.airlinemeals.net under SAS. They are also Star alliance so you can accrue miles.