These include:
Austin: The state capitol and most state office buildings, and half the other downtown buildings. A lot of granite has been used in the construction of Austin-Bergstrom airport. The mural of Enchanted Rock is also quite nice. It's too bad you have to go to the stinking airport to see it.
Chicago: 1st National Bank Building (exterior)
Denver: Some of the granite used in construction of the new Denver airport is Llano granite.
Gulf Coast of Texas: Llano granite is widely used for jetty construction.
Houston: Niels Esperson Building (base)
Texas Company Building (base)
Los Angeles: Times Building
L.A. County Courthouse
New York City: 2 wings of the American Museum of Natural History
exterior walls at Grand Central Station
Minneapolis: Prudential Life Insurance Building
Washington D.C.: Sam Rayburn Congressional Office Building
TMG has also been widely used for gravestones (I know it's available in Tennessee and Ohio, but apparently not in Pennsylvania). The granite used for Elvis Presley's gravestone may be TMG (or could be from Minnesota).
[list compiled from several sources, some a bit old, so names may have changed]
