I like the best examples of all styles, but prefer Modernism. If you look at any one style you can find buildings to appreciate even if its not quite your cup of tea. For example, I can totally appreciate the sarcastic Post Modernism of people like Graves, Venturi, and Tigerman, but I can't stand the shit that Johnson shat out towards the end of his career. Don't even get me started on the concrete box with holes in it Neo-Classicism of people like Lucien LaGrange.
While I like some PoMo buildings and totally love a few like Stanley Tigerman's Anti-Cruelty Society in Chicago, Modernist buildings like Mies' apartment towers, Goldberg's Marina City and River City, and The Barbican are what really do it for me. That said, any city that lacks a good mix of all styles completely turns me off. That's why I have a huge thing for Chicago, its got an even mix of literally every style for the past 150 years with a little extra emphasis on Modernism.
Good PoMo:
Chicagotribune.com
Notice that the entryway of the building is designed to look like the muzzle and face of a dog. This mixes up Modernist geometries and reflects the use of the building. Now that is how PoMo should be used, none of this comical aping of historical styles.