I am interested to know which courses all of you out there would love to get your hands on and modify. I can think of several great courses that I feel could still be substantially improved upon (ignoring legal and financial limitations).
Royal County Down - I would excise 10-12, 14, and 16-18 and modify 15. I would steal 2 holes from Annsley and thread 4 new holes through the dunes behind the front 9.
Royal Portrush - I would excise 10, 11, and 15-18, and I would thread six new holes from the Valley (including holes 5 and 6).
Royal Aberdeen - The greens could be far more interesting, the bunkering could be improved, and a few holes on the back 9 could be modestly rerouted.
Cypress Point - Great course, but given the natural attirbutes it could be even better. The routing essentially stays, but the bunkering and tie-ins would be modified to take full advantage of the surroundings and the greens would be recontoured to add even more fun. As for the 18th hole, couldn't it be routed parallel to the 17th with a green pirched by the cliffs somewhat near the 16th tee?
Spansih Bay, Bandon Dunes, etc.
Anyway, I really just mention these musings for illustrative purposes. My goal is to see what courses the rest of you would tinker with if you had your drothers.