As of today:
Top 5 (No particular order):
St Andrews Old
Ballybunion Old
Pine Valley
Kingsbarnes
Baltimore CC Five Farms
6 Through 15 (No particular order):
Leven
Tobacco Road
Baltusrol Lower
Dormie Club
Saucon Valley Old
Lehigh CC
Lancaster CC
St Andrews New
Hershey CC West
CC of York
16 Through 25 (No particular order):
Carnoustie
Dooks
Baltusrol Upper
Saucon Valley Weyhill
Philly Cricket Wissahickon [Pre-renovation - Post-renovation could move this up to the higher grouping based on the posted progress]
Philmont North
Crail Balcomie [tough because the location is so magical, the course generally doesn't merit the higher grouping though]
Saucon Valley Grace
Mid-Pines
Mark Twain GC [yes, it is that good]
Others I considered: Hershey CC East, DuPont, Fota Island Deerpark Course, Ballyhack, West Shore CC and Lebanon CC