Still because we have time, this might not make a top 10 building list, but it might make my top 10 buildings to sit across the street from at a sidewalk bistro eating cheese fondue and drinking a good riesling all evening long: Château Frontenac, Quebec City, Quebec
I still have buildings in the list... Villa Savoye, Poissy, France (Le Corbusier): I didn't expect this one to go undrafted. Palazzo Farnese, Rome (Sangallo and Michelangelo) Palacio Güell, Barcelona, Spain: More info here, IMHO this is a better piece of architecture than the Casa Batlló: http://hanser.ceat.okstate.edu/6083/gaudi/guell_palace.htm
the PSFS building in Philadelphia, the first modern skyscraper, preceding the Seagram's building by 20 years. it was the first skyscraper to bare a name atop the structure. they did it not to be the first, but to cover the heating/cooling structure atop the building. The Philadelphia Museum of Art The University Club of Chicago Cathedral Hall
University Club of Chicago The Edsel Ford House, Grosse Pointe, Michigan "The High" (had to give props to my high school)
Interesting Buildings in Merida, Yucatan Palacio Canton (currently houses the Regional Anthropology Museum) Palacio Municipal Casa de Montejo
I have selected the National Swimming Centre for the 2008 Beijing Olympics. I actually wanted the Olympic Stadium.
A few Istanbul buildings are chosen, but none by the great Turkish architect, Sinan. Here is one..... The Selimiye at Edirne, Turkey
Recitation Hall, Wittenberg University AD White House, Cornell University Harvard Hall, Harvard College
now that I got off my education kick, my three favorite Detroit buildings, all designed by Albert Kahn, Detroit's most notable architect. In addition to these buildings, he designed numerous auto factories and houses. the Fisher Building the GM Building the Whitcomb Conservatory, Belle Isle
Other Interesting Buildings Don't know if the Bopper already selected it... but the Universidad de Guanajuato is pretty nice:
Ok, I have to get one more from academe La Universidad de Sevilla, or as it is otherwise known, 'La Fabrica'. It once housed a Tobacco Factory and basically constitutes a maze nowadays. It is also the major setting for the play 'Carmen'.