The only course on the rota for which I have no fond feelings is Royal Birkdale. It has some big dunes, but it doesn't use them for anything but framing; the bunkering is less engaging than any of the other venues; and the greens are blah, too. It's a stout test of golf but that's all. Ninth of nine on my list -- a 7 on the Doak scale.
I realize some people find Royal Lytham & St. Annes and Royal Troon and Royal Liverpool and Carnoustie charmless, but I think those people are too taken by setting -- all four courses have more interesting holes and more interesting bunkering than Birkdale. I think all four of these courses are pretty close together, as they are all 8's on the Doak scale. If I had to rate them, I'd put them in the order above, from best to worst. I'd guess most posters would put them almost the other way around, but I think that the rest of you are too heavily influenced by however the last Open happened to play out, which is largely a matter of luck. Lots of courses could correctly identify Sergio Garcia as not worthy.
That leaves Turnberry fourth on my list -- another 8 on the Doak scale, but undeniably a better setting for golf than the others.
Royal St. George's is third -- a solid 9. If I were to choose to play one or the other tomorrow, I would go with Sandwich over Muirfield, but only because I've played Muirfield far more often.
Muirfield and St. Andrews both got 10's in my book. The Old Course is still far ahead, because Muirfield relies too much on its impenetrable rough.
So, for those of you who just like to read lists:
1. St. Andrews
2. Muirfield
3. Royal St. George's
4. Turnberry (Ailsa)
5. Royal Lytham & St. Annes
6. Royal Troon
7. Royal Liverpool
8. Carnoustie
9. Royal Birkdale
There are easily 20 other links courses I'd rather play again than Birkdale.