Sorry, I'm just now checking back in on this thread. A few thoughts:
Sean makes a good point about the effect of trees. But if trees are not the defining feature of the dogleg, then there has to be some other hazard or obstacle creating largely the same effect. Without that, then there really isn't a dogleg is there?
I didn't intend the reference to "approaching 90 degrees" to be taken so literally. Seems to me anything in the 75 degree range (perhaps even a bit less) would qualify. My point was just that the dogleg needs to be severe. I think it is that severity that makes this type of hole hard to design because it tends to exclude options off the tee rather than create them. Show me a sharp dogleg that has multiple viable lines of play off the tee and I think you are well on your way to identifying the best ones.
Many of the nominations so far I think prove my point that these are tough holes to design well. Sure they are sharp doglegs. But are they "truly great" holes? I'm not sure some of them are even among the best holes on their course. Of those mentioned so far, I have played 6 (Grandfather #16, Baltimore Five Farms #6, Pine Needles #10, Bandon Dunes #4, Bandon Trails #14 and Whistling Straits #5). I don't view either of the Bandon holes as sharp doglegs. Of the others, the only one that I think potentially qualifies as great is Five Farms #6. Even there, I'm not sure it is the best par 5 on the course, although that is more a testament to #14 than a detraction against #6.
Ed