I'll have to agree with Bryson. The Philadelphia Art Museum is probably the best
large neoclassical building I've seen yet (some smaller gems by Cret, like the inner building of the Rodin museum, are arguably better). The warm color of the stone and colorful terra-cotta ornament liven up what is often a rather cold architectural style (see the National Archives building in DC for a similar, but much more dull, contemporary example), its proportions are wonderful, and its siting is nearly perfect.
closest thing to the Acropolis in America?
I'm amazed at your choices Bryson, but given your modernist proclivities, it at least makes sense that you picked two finely proportioned buildings. The Wrigley Building, while it has great detailing, is just a big pile with a tower stuck on it, much like NYC's City Hall. I'm sure we'll see a lot like it in this thread. Anyway I've actually been meaning to ask, what's your opinion on the PECO tower on Market? Personally I think it's a rather exceptional international style black box, even if it is a bit late. It's got great slim proportions and I'm pretty sure the cantelevered west and east facades of the tower, along with the vertical piers, are alluding the PSFS: