In a town as old and cultured as Boston, I figure there are way too many to count. But I'll cite three as *special mentions*, for a variety of reasons:
1 Winter St. aka the Corner Mall building
1.) Overshadowed by its contemporary across the street, the Burnham Building, along with several other neo-Gothic/Beaux Arts jewels in Downtown Crossing from the building boom of ca. 1880-1920.
2.) Hated at ground-level for the badly dated, vintage 80s [but not in a good way] Corner Mall marquee (aka Fast Times at Ridgemont High)
3.) But oh, those repeating gargoyles! They make up for everything as far as I'm concerned:
https://farm1.staticflickr.com/56/121650883_20d0ef37c4_z.jpg
The McCormack Courthouse
1.) Built between 1931-33 during the depths of the Depression, as the global picture darkened immensely with the rise of Hitler, Mussolini, Stalin, and Japan's fascist regime.
2.) Yet that did not preclude the architects from adding numerous fascist motifs strung along the top parapets (tough to see in this photo, but they're there, trust me--easily viewed from 50 Milk St.)
http://www.rdkengineers.com/images/Government/McCormack%20Post%20Office_Courthouse_For%20Ned_VERTICAL.jpg
3.)
The Grain Exchange Building
It used to be so much cooler when the big holiday bow was tied around it each Christmas season. Of course, the only reason for that was so drivers on the Elevated Artery could see it. So to restore the building to its former prominence, you'd have to rebuild the Artery. Let's not go there....
http://content-rb.related.com/SiteCollectionImages/Related%20Beal/CUT%20SHEETS/177%20Milk%20Street,%20Boston%20-%20Grain%20Exchange/Main.jpg