In light of the piazza news in Troy, some of my co-workers and I thought it would be fun to list some of the more famous piazzas in the world (well, mainly in Italy).
I have fond memories of some of Europe's piazzas - the memories mainly include me walking around with a variety of gelatos (usually recipes involving chocolate and hazelnut) while admiring the beautiful architecture and wishing it would come back with me to New York.
Well, I may not get the Duomo in Troy, but we are getting a piazza at the end of Broadway. Now we just need Gelateria Lisa to move to Monument Square and I am set.
These are some of the must-see piazzas. Maybe one day Troy will make the U.S. list. :)
Rome:
Piazza Fontana di Trevi - Everyone (or at least nearly everyone) has heard of the Trevi Fountain. Well, there's a reason for it. It's immense and amazing.
Piazza San Pietro - This is the piazza at the entrance of St. Peter's Basilica. You've probably seen Pope-broadcasts from here with millions of Catholics filling the space. (I remember getting a really nice gold watch for my dad here...but then, upon further inspection, I thought it was too girly since it had flowers on it and I kept it for myself and got him a pocket watch from Sicily instead).
Piazza Venezia - The beautiful image of this piazza with its famous monuments atop a hill in Rome stays with you for a very long time. I still remember walking down its steps. (which brings me to the...)
Piazza di Spagna - The Spanish Steps in Rome has inspired visitors, artists, and writers since the 18th century. It's nearly impossible to have not seen a painting of it (my favorite is by F. Childe Hassam). I remember there being a McDonald's nearby when I visited which kinda ruined the mood; apparently it was the oldest McDonald's in Italy though built in the late 1980s, according to a plaque there.
Florence:
Piazza Santa Croce - The main building in this very old plaza was built by the architect of the Medici family.
Venice:
Piazza San Marco - (St. Mark's Square) Though this piazza is sometimes famously submerged in the ever-sinking city, St. Mark's Basilica in the square is absolutely amazing with Catholic drawings, and opulent gold details.

Brussels:
Grand Place - This is technically a central square but I think it counts as a non-Italian piazza (especially if Troy's counts as a piazza). The place is also near the country's Little Man Peeing statue which has become a symbol of the country, marking a care free attitude/fun - or so my AAA tour book said.
Piazzas are basically a place for people to come together (they're also great for people watching). The $30 million development in Troy, I think, will be a welcomed edition to the city.