Augusta National hosts a major every year. Every great professional player and quite a few amateurs from the 1930s onward have played there. It is hard to argue against that course if we are limiting our discussion to America.
If not Augusta National, I would have to say Merion East. There have been more USGA championship events there than any other club. Within an eight year span (2005-2013) Merion will have hosted the US Amateur, the Walker Cup and the US Open, for its 19th USGA championship:
1904,1909,1926,1949 Women's Amateur
1916,1924,1930,1966,1989,2005 Men's Amateur
1934,1950,1971,1981,2013 US Open
1954 Curtis Cup
1960 Eisenhower Trophy
1998 Girl's Junior
2009 Walker Cup
The 1930 Amateur and 1950 Open are among the finest championship tournaments in American golf.
Why do you say Pebble, Jim?