Generally speaking I like the following
front to back greens are often almost imperceptible
combo of slight tilt of greens away from "minor" trouble on the high side
slightly raised (maybe 18 inches) green front to compound the ground game/chip approach...Hoylake features this sort of thing quite a bit
on rumbling terrain, one larger dip which takes a good shot to get past and is hard to see properly...if the fairway turns slightly just beyond this dip its even better
bunkers in no man's and thus usually completely ignored until a strong contrary wind turns up
A very cool feature which I don't think I have seen anywhere else is the rear funnel at Palmetto's 11th. It isn't noticeable on the tee, but when chipping it looms in the background.
Not at all visible from the fairway, the 6th at St Georges Hill has a cool dip shy of the green.
Huntercombe has a lot of in your face features, but the swale shy of the 9th green is blind and sublime.
I am a big fan of odd looking earthworks on courses, especially around greens. A really cool feature is when ramps are created whereby the lucky golfer can use them for a ground game play. The idea fits in wonderfully with the concept golf and luck....Kington's 12th.
I like it when an archie's work is utilized in the course presentation. Often times, course presentation alters architecture for the worse. If a green is meant to roll over a hump, then the greens should be slow enough to allow this to be the case. Its a small detail with a potentially large impact on playability. Leckford Old's 4th.
Ciao