Jim:
David Tepper probably knows this area as well as anyone on the board; he'll have good suggestions.
In addition, I think Mike Hendren's advice about "getting away" from the usual suspects is quite sound. Part of the great allure of Scotland as a place to play golf is to experience it as the Scots do -- an everyday thing that all manner of folks participate in. Some of my best memories of golfing in Scotland were the unplanned, serendipitous rounds and clubhouse conversations with members of less-than-well-known courses.
I've played a few of the courses among those mentioned, and here are some thoughts:
-- If you play Cruden Bay, it's well worth it to make the short-ish trip up to Fraserburgh -- a very good links course (save for the 1st and 18th holes) that gets a lot less play from Americans than Cruden Bay. Some Scots -- not all, but more than a few -- consider Fraserburgh a better overall links course. I wouldn't go out of my way to play Peterhead -- decent, but not as good as Fraserburgh. For a truly crazy, out-of-this-world round in the Aberdeen area that shouldn't take you more than 2+ hours -- with incredible views and a great old clubhouse -- try Stonehaven. Maybe a late evening round? Easy to do in less than 3 hours, and something you won't forget.
-- Depending on how you arrive, and where you are based, the road from Cruden Bay to Moray/Nairn is quite slow -- the better part of half-a-day. But, it is wonderfully scenic, and Cullen is a very sporty, fun little course along the way. It gets very little play from the American crowd, and thus it's all the more welcoming to visitors from here. You play among the giant sea stacks that dot the course.
-- Boat of Garten is well worth a round -- it's not that far south of Inverness, and conveniently located just a few minutes off the A9. A very good inland course, tougher than its short length might suggest, and a great setting amid the Cairngorms. A change of pace, and a very interesting one, from links courses. Designed by James Braid. The Boat Hotel is pretty good as far as local accomodations if staying overnight.
Among the GCA crowd, Dornoch and Brora are probably must plays, and probably repeat plays as well. Nairn and Tain get mixed reviews from the GCA crowd, but Fortrose & Rosemarkie has been generally well-reviewed here. There is a little 9-hole links course east of Tain called Portmahomack that David Tepper might know -- again, one of those little-known Scottish courses that gets very little American play. And not far from Dornoch is a little, quite hilly course called Strathpeffer Spa that David T. may know about. Said to hold some interest, and great views.
Lots of good choices -- but I'd highly recommend getting away from the belt-notchers for at least a day to play a course few folks encounter on their Scotland trips. They are well worth seeking out.