For a long time now Dusit has been just about the best Thai restaurant in Edinburgh (and I've been going for years - from back when you had to go to the pub next door to get your drinks).
Not that I've exactly tried all the others, but I've tried a few, from the hilariously punning, and rather swanky Thai Me Down (since closed), to the Thai Lemongrass (short) chain of restaurants, and Dusit has consistently out-performed them all.
The food is rich, inventive and well-spiced and though I suspect it isn't the most authentic, it's always been pretty damn tasty. They seem to do a lot more steak than you would normally expect, but they do it well.

If I have a gripe it's that now they are famous and enormously popular, they have adopted a policy of allotting each booking a very tight eating slot, and are determined to shove their diners out of the door as soon as they show any sign of flagging. And sometimes even if they don't. Add to this the slightly cramped but crowded surroundings and you certainly wouldn't want to go there for a quiet relaxing meal.
Maybe it would be worth trying their takeaway service instead?

Last time I went there with my flatmate Jenny and her Beau Alistair so here's some randomly poor photos of us eating their food...