Heritage is also worth consideration. I personally would rather play Heritage and Caledonia back-to-back than True Blue and Caledonia.
I agree. I really love the Heritage. If it didn't have such tight housing, it would be one of my favorites anywhere. On Myrtle Beach trips, I usually try to play 36 at Heritage, the only course we usually play twice.
If I had 72 holes to play I'd play Heathlands, Caledonia, True Blue, and Heritage.
And I'd try not to play Caledonia & True Blue the same day. Heritage is right beside them, so you could mix it up.
Plus, if you have flexibility on lodging, 3 of these 4 are on Pawleys Island and you can avoid the masses.
A sleeper pick -- try Pawleys Plantation. Located towards the south end of the Grand Strand.
This is also near Heritage, TB, and Caledonia but I really do not like this course. To each his own, and a member of our usual group loves it so we usually play it. I particularly dislike the par 3s back on the bay -- though I understand it was the Army Corps of Engineers that destroyed these two holes, not Nicklaus.