No point in listing personal favorites, nor modern courses, when there are so many prestigious old-line clubs that want to host. USGA politics rule this selection; it's doubtful you'll find a host site that doesn't have a member on the Selection Committee or among the current officers of the USGA. I don't know how many my list will be -- certainly not enough to cover the next 60 years of U.S. sites -- but here are some places that might have the clout to get it someday:
Peachtree Golf Club, GA
San Francisco Golf Club, CA
Cherry Hills, CO
Hazeltine National, MN
Milwaukee CC, WI
Champions GC, TX
Plainfield CC, NJ
Quaker Ridge, NY
Aronimink, PA
Bandon Dunes Resort, OR - the only modern venue on my list, and there only because Mike Keiser has a lot of respect within the USGA and will host other events too. No idea which course they would use. Give it another 15-20 years. The only other modern venue I could see would be Austin Golf Club, if they wanted it.